As an aid, feel free to use the following questions to help you generate content for your entries:

• What action or concept of significance, as related to the course, did you experience on this date?

In the first days of class concepts of significance that I have taken away from said learning are:

svn add and svn commit actions.

pointers, using pointers in C programming code.

integers, chars, using integers and chars as pointers, using integers and chars in C programming code.

include action, using include actions in C programming to use libraries.

• Why was this significant?

The svn commands are great for saving information to your directories and committing changes.

The pointers are used to have something exist in memory but no be contained in a certain place.

The integers and chars can be used to declare variables.

The include action is used to reference pre-existing libraries contained in the C programming language.

• What concepts are you dealing with that may not make perfect sense?

Something that does not make perfect sense to me at this point in the class so far is the “%u\n” “%d\n” portions of code.

• What challenges are you facing with respect to the course?

My challenge with a C programming course is that I have no previous experience with a programming language, a lot of new information to grasp.

With this in class example we used pointers, malloc, a while loop, if condition, else and else if condition, srand, time, NULL,

malloc was a call for an allocation of memory.

While loop with conditions was our implementation to keep the program running for more than one instance.

srand was our pseudo random number generator.

time was our value system of numbers that srand used to return random numbers? I think.

If I remember correctly when you NULL something you are acknowledging that it exists without physically or logically assigning it a specific value, out it's were the integer pointers input and pick.

We also talked about how it was difficult for a computer to be random without eventually becoming predictable in some way, due to the facts of the way a computer operates always following instructions, and not having the distinct ability to make a decision on it's own accord.

#include<stdio.h>

#include<stdlib.h>

int main()

{

int *input, *pick; input=pick=NULL;
input=(int *)malloc(sizeof(int)*1);
pick=(int *)malloc(sizeof(int)*1);
*input=0;
*pick=0;
while(*pick !=-1)
{
	srand(time(NULL));
	*pick=rand()%99+1;
	printf("Guess the computer's pick: ");
	scanf("%d", input);
	if(*input==*pick)
	{
		printf("Congratulations you have won\n");
	}
	else if(*input > *pick)
	{
		printf("Your guess was high\n");
	}
	else
	{
		printf("Your guess was low\n");
	}
	printf("Computer had %d\n", *pick);
	printf("0 to play again, -1 to quit\n");
	scanf("%d", pick);
}
return(0);

}

With this class example we used new C/C++ components argc and argv

argc in C/C++ is the argument count within a programs pseudo code, we used the argument counter in this program to say that if the argument count was less than 2 the program would print a string message to the user telling them that need more arguments and how many arguments they actually provided.

argv is an abbreviation for an argument vector, we used argv as a double pointer character, that is really the best I can explain what this is doing at this point.

#include<stdio.h>
#include<stdlib.h>
int main(int argc, char **argv)
 
{
	unsigned char i;
	if(argc<2)
	{
		printf("%8s must be run with 1 or more arguments, you only provided %hhu\n",(argc-1));
		exit(1);
	}
	printf("You ran this program with %hhu arguments, they are:\n",(argc-1));
	for(i=1;i<argc;i++)
	{
		printf("argv[%hhu]: %s\n",i,*(argv+i));
	}
	return(0);
}

I am adding all of the coded examples that we have done in class so far as my 4th opus entry. Probably add some textual content about what each program was focusing on once I get the format of the entry all setup with the all the examples included.

Example 1

#include
<stdio.h>
int main()
 
{
	printf("an int is %u bytes\n", sizeof(int));
	return(0);
}

Example 2

#include
<stdio.h>
int main()
{
	int a;
	a=0;
	printf("a contains %u\n", a);
	printf("a's address is 0x%x\n", &a);
	return(0);
}

Addition to var2.c
#include<stdio.h>
int main()
{
	int a=0;
	int *b;
	b=&a;
	*b=12;
	printf("a contains %u\n", a);
	printf("a's address is 0x%x\n", &a);
	printf("b contains %u\n, *b);
	printf("b points to 0x%x\n, b);
	printf("b's address is 0x%x\n",&b);
	return(0);
}	

Example 3

#include<stdio.h>
int main()
{
	int v=17;  //setting the integer v equal to the number 17
	int *p1=NULL; //setting the pointer p1 to NULL, NULL is allowing p1 to exist without 				assigning an exact value
	printf(“v is %u\n”, v);  //having the computer display or “print out” the value of v
	p1=&v;
	printf(“*p1 is %u\n”, *p1);
	*p1=53;
	printf(“v is %u\n”, v);
	printf(“*p1 is %u\n”, *p1);
	v=7;
	printf(“v is %u\n”, v);
	printf(“*p1 is %u\n”, *p1);
	return(0);
}

Example 4

#include<stdio.h>
int main()
{
	int num=0;
	printf(“Please enter an integer value: “);
	scanf(“%d”,&num);
	printf(“You just input %d\n”,num);
	if((num % 2) == 0)
	{
		printf(“It is even.\n”);
	}
	else
	{
		printf(“It is odd.\n”);
	}
	return(0);
}

Example 5

#include<stdio.h>
#include<stdlib.h>
int main()
{
	int *p1,*p2,**p4;
	p1=(int *)malloc(sizeof(int)*1);
	*p1=26;
	printf("*p1 is %u\n",*p1);
	p2=p1;
	p4=&p1;
	printf("**p4 is %u\n",**p4);
	printf("*p2 is %u\n",*p2);
	*p2=61;
	printf("*p1 is %u\n",*p1);
	printf("**p4 is %u\n",**p4);
	printf("*p2 is %u\n",*p2);
	**p4=16384;
	printf("*p1 is %u\n",*p1);
	printf("**p4 is %u\n",**p4);
	printf("*p2 is %u\n",*p2);
	return(0);
}

Example 6

#include<stdio.h>
#include<stdlib.h>
int main()
{
	int *input, *pick; input=pick=NULL;
	input=(int *)malloc(sizeof(int)*1);
	pick=(int *)malloc(sizeof(int)*1);
	*input=0;
	*pick=0;
	while(*pick !=-1)
	{
		srand(time(NULL));
		*pick=rand()%99+1;
		printf("Guess the computer's pick: ");
		scanf("%d", input);
		if(*input==*pick)
		{
			printf("Congratulations you have won\n");
		}
		else if(*input > *pick)
		{
			printf("Your guess was high\n");
		}
		else
		{
			printf("Your guess was low\n");
		}
		printf("Computer had %d\n", *pick);
		printf("0 to play again, -1 to quit\n");
		scanf("%d", pick);
	}
	return(0);
}

Example 7

#include<stdio.h>
#include<stdlib.h>
 
int main()
{
        char *value,i;
        value=(char *)malloc(sizeof(char)*4);
        *(value+0)=0;
        *(value+1)=1;
        fprintf(stdout, "please enter a value (-128-+127):");
        fscanf(stdin,"%hhd",&i);
        *(value+2)=i;
        *(value+3)=(2*i)+3;
        for(i=3;i>=0;i--) //(i=0;i<=3;i++)
        {
                printf("%hhd\n",*(value+i));
        }
        return(0);
}

Example Sample

#include<stdio.h>
#include<stdlib.h>
int main(int argc, char **argv) //parameters are in the ( ), first parameter of main must be an integer
{
        unsigned char i;
 
        if(argc<2)
        {
                printf("%8s must be run with 1 or\
 more arguments, you only provided %hhu\n",*(argv+0),(argc-1));
                exit(1); // \ followed by enter allows you to continue code on new line
        }
        printf("You ran this program with %hhu arguments, they are:\n",(argc-1));
        for(i=1;i<argc;i++)
        {
                printf("argv[%hhu]: %s\n",i,*(argv+i));
        }
        return(0);
}

Example FileFun

#include<stdio.h>
#include<stdlib.h>

int main()
{
        FILE *in,*out;
        char value=0;
        in=fopen("file.txt","r");
        out=fopen("out.txt","w");
        if(in==NULL)
        {
                printf("ERROR!\n");
                exit(1);
        }
        fscanf(in,"%hhd",&value);
        while(value != -1)
        {
                value*=2;
                fprintf(out,"%hhd\n",value);
                fscanf(in,"%hhd",&value);
        }
        fclose(in);
        fclose(out);
        return(0);
}

Project 0 or as I like to call it range.c

#include <stdio.h>
#include <math.h>
int main()
{
    // Variables
    unsigned long long int quantity = 0;
    unsigned char uc = 0;
    signed char sc = 0;
    unsigned short int usi = 0;
    signed short int ssi = 0;
    unsigned int ui = 0;
    signed int si = 0;
    unsigned long int uli = 0;
    signed long int sli = 0;
    unsigned long long int ulli = 0;
    signed long long int slli = 0;
    // Display information for unsigned char data type
    printf("An unsigned char is %d bytes\n", sizeof(uc));
    printf("The range of an unsigned char is %hhu to %hhu\n", uc, (uc-1));
    quantity = (unsigned char)(uc-1) + 1;    // What does this line do?
    printf("An unsigned char can store %llu unique values\n\n", quantity);
    // Display information for signed char data type
    printf("A signed char is %d bytes\n", sizeof(sc));
    quantity = (unsigned long long int)pow(2, (sizeof(sc)*8)); // What is happening?
    printf("The range of a signed char is %hhd to %hhd\n", (sc-(quantity/2)), (sc+(quantity/2)-1));
    printf("A signed char can store %llu unique values\n\n", quantity);
    // Display information for unsigned short int data type
    printf("An unsigned short int is %d bytes\n", sizeof(usi));
    printf("The range of an unsigned short int is %hhu to %hhu\n", usi, (usi-1));
    quantity = (unsigned short int)(usi-1) + 1;    // What does this line do?
    printf("An unsigned short int can store %llu unique values\n\n", quantity);
    // Display information for signed short int data type
    printf("A signed short int is %d bytes\n", sizeof(ssi));
    quantity = (unsigned long long int)pow(2, (sizeof(ssi)*8)); // What is happening?
    printf("The range of a signed short int is %hhd to %hhd\n", (ssi-(quantity/2)), (ssi+(quantity/2)-1));
    printf("A signed short int can store %llu unique values\n\n", quantity);
    // Display information for unsigned int data type
    printf("An unsigned int is %d bytes\n", sizeof(ui));
    printf("The range of an unsigned int is %hhu to %hhu\n", ui, (ui-1));
    quantity = (unsigned int)(ui-1) + 1;    // What does this line do?
    printf("An unsigned int can store %llu unique values\n\n", quantity);
    // Display information for signed int data type
    printf("A signed int is %d bytes\n", sizeof(si));
    quantity = (unsigned long long int)pow(2, (sizeof(si)*8)); // What is happening?
    printf("The range of a signed int is %hhd to %hhd\n", (si-(quantity/2)), (si+(quantity/2)-1));
    printf("A signed int can store %llu unique values\n\n", quantity);
    // Display information for unsigned long int data type
    printf("An unsigned long int is %d bytes\n", sizeof(uli));
    printf("The range of an unsigned long int is %hhu to %hhu\n", uli, (uli-1));
    quantity = (unsigned long int)(uli-1) + 1;    // What does this line do?
    printf("An unsigned long int can store %llu unique values\n\n", quantity);
    // Display information for signed long int data type
    printf("A signed long int is %d bytes\n", sizeof(sli));
    quantity = (unsigned long long int)pow(2, (sizeof(sli)*8)); // What is happening?
    printf("The range of a signed long int is %hhd to %hhd\n", (sli-(quantity/2)), (sli+(quantity/2)-1));
    printf("A signed long int can store %llu unique values\n\n", quantity);
    // Display information for unsigned long long int data type
    printf("An unsigned long long int is %d bytes\n", sizeof(ulli));
    printf("The range of an unsigned long long int is %hhu to %hhu\n", ulli, (ulli-1));
    quantity = (unsigned long long int)(ulli-1) + 1;    // What does this line do?
    printf("An unsigned long long int can store %llu unique values\n\n", quantity);
    // Display information for signed long long int data type
    printf("A signed long long int is %d bytes\n", sizeof(slli));
    quantity = (unsigned long long int)pow(2, (sizeof(slli)*8)); // What is happening?
    printf("The range of a signed long long int is %hhd to %hhd\n", (slli-(quantity/2)), (slli+(quantity/2)-1));
    printf("A signed long long int can store %llu unique values\n\n", quantity);
    return(0);
}

Project 1 or as I like to call it Project2.c and Project2.1.c

#include<stdio.h>
#include<stdlib.h>
 
int main()
{
        FILE *message, *key, *cipher;
        char c, fname[] = "message.txt";
        char code[] = "key.txt";
        int keyvalue;
 
        message = fopen(fname, "r");
        key = fopen(code, "r");
        cipher = fopen("cipher.txt", "w");
 
        c = fgetc(message);
        fscanf(key,"%d",&keyvalue);
 
        printf("Message is: ");
 
        while(c != EOF)
        {
                fprintf(stdout, "%c", c);
                c = fgetc(message);
        }
 
        fclose(message);
        message = fopen(fname, "r");
        c = fgetc(message);
 
        printf("Cipher is: ");
 
        while(c != EOF)
        {
                if((c >= 65) && (c <= 'Z'))
                        c = c + keyvalue;
                else if((c >= 'a') && (c <= 'z'))
                        c = c + keyvalue;
 
                fprintf(stdout, "%c", c);
                fprintf(cipher, "%c", c);
                c = fgetc(message);
        }
        fclose(message);
        fclose(key);
        return(0);
}

#include<stdio.h>
#include<stdlib.h>
 
int main()
{
        FILE *cipher, *key, *decipher;
        char c, fname[] = "cipher.txt";
        char code[] = "key.txt";
        int keyvalue;
 
        cipher = fopen(fname, "r");
        key = fopen(code, "r");
        decipher = fopen("decipher.txt", "w");
 
        c = fgetc(cipher);
        fscanf(key,"%d",&keyvalue);
 
        printf("Cipher is: ");
 
        while(c != EOF)
        {
                fprintf(stdout, "%c", c);
                c = fgetc(cipher);
        }
 
        fclose(cipher);
        cipher = fopen(fname, "r");
        c = fgetc(cipher);
 
        printf("Decipher is: ");
 
        while(c != EOF)
        {
                if((c >= 65) && (c <= 'Z'))
                        c = c - keyvalue;
                else if((c >= 'a') && (c <= 'z'))
                        c = c - keyvalue;
 
                fprintf(stdout, "%c", c);
                fprintf(decipher, "%c", c);
                c = fgetc(cipher);
        }
        fclose(cipher);
        fclose(key);
        return(0);
}

What will happen if I take the ; off the end of a statement and try to compile the program.

lab46

Based on what I have learned thus far about c programming I think there would be an error in trying to compile the program.

I believe it would be considered a syntax error and the would be the reason there would be an error in trying to compile.

I am going to experiment on a hello world program we wrote in class this semester on lab46

lab46:~$ nano hello.c
lab46:~$ gcc -o hello hello.c
hello.c: In function 'main':
hello.c:5: error: expected ';' before 'return'
lab46:~$

Based on the data collected:

• Was your hypothesis correct?

yeah I am pretty good.

• Was your hypothesis not applicable?

it was applicable

• Is there more going on than you originally thought? (shortcomings in hypothesis)

no sir.

• What shortcomings might there be in your experiment?

intelligence.

• What shortcomings might there be in your data?

data is good.

make sure you put ; at the end of applicable statements.

What happens if you do not include a return; at the end of your program/function.

lab46

I am not entirely sure I am assuming I will get some sort of syntax error but to be sure I will have to run it to find out.

I am going to use my hello world! program once again that is deployed on lab46

lab46:~$ nano hello.c
lab46:~$ gcc -o hello hello.c
lab46:~$ nano hello.c
lab46:~$ ./hello
Hello, World!

Based on the data collected:

• Was your hypothesis correct?

No sadly I was wrong the program still ran and now I feel foolish.

• Was your hypothesis not applicable?

it was.

• Is there more going on than you originally thought? (shortcomings in hypothesis)

apparently :O

• What shortcomings might there be in your experiment?

intelligence.

• What shortcomings might there be in your data?

none.

The program still ran and complied with the return; statement line removed.

I am going to attempt to add the multiplication portion of project 2 into project 2.

I used the other functions addition and subtraction that I had help writing, more so addition because I figured add and multiply are alike in common sense than subtraction.

The goal is that it will work in the program just the way the other functions do and multiply my 4 digit numbers correctly. oh yeah and compile. hopefully.

I wrote the code (at least it seems like working code to me) into the program and I will attempt to compile it and run it on lab46

lab46:~/src/cprog$ nano bignum.c
lab46:~/src/cprog$ gcc -o bignum bignum.c
lab46:~/src/cprog$ ./bignum
How many digits are in your largest number?
4
Please enter 1 to Add, 2 to Subtract, 3 to Multiply, 4 to Divide
3
Enter your first number
0010
Please enter your second number
0010
01870
lab46:~/src/cprog$

Based on the data collected:

• Was your hypothesis correct?

no it was not my program told me 10×10 = 1870

• Was your hypothesis not applicable?

it was.

• Is there more going on than you originally thought? (shortcomings in hypothesis)

i have no idea.

• What shortcomings might there be in your experiment?

knowledge of how to program

• What shortcomings might there be in your data?

the intended answer.

I did not get the correct answer, I will have to figure it again a better way that produces the intended answer.

The fact that I can not figure out how to use atoi has led me to use this opus entry on Type Conversions.

The C Programming Language 2nd edition by Kernighan and Ritchie says

“When an operator has operands of different types, they are converted to a common type according to a small number of rules. In general the only automatic conversions are those that convert a “narrower” operand into a “wider” one without loosing any information… A char is just a small integer, so chars may be freely used in arithmetic expressions. This permits considerable flexibility in certain kinds of character transformations. One is exemplified by this naive implementation of the function atoi, which converts a string of digits into its numeric equivalent.”

/* atoi: convert s to integer */
int atoi(char s[])
{
    int i, n;
 
    n = 0;
    for (i = 0; s[i] >= '0' && s[i] <= '9'; ++i)
        n = 10 + n + (s[i] - '0');
    return n;
}    

That is all I really read and found in the book/index that specifically talked about the atoi function.

C Pocket Reference by Prinz & Kirch-Prinz

Conversion Between Strings and Numbers

“A variety of functions are declared in the header file stdlib.h to obtain numerical interpretations of the initial digit characters in a string. The resulting number is the return value of the function.”

int atoi( const char *s );
    /*Interprets the contents of the string s as a number with type int.  The analogous functions atol(), atoll()(*),
    and atof() are used to convert a string into a number with type long, long long(*), or double.*/

And that is pretty much what that book had to say about my problem so I guess I will go ahead and try to work on implementing this into my project bignum.c

for(x = digit1; x >= 0; x--)
{
    *(result+x) = *(value1+x) + *(value2+x) + *(result+x);
    if(*(result+x) > 9)
    {
        *(result+x) = *(result+x) - 10;
        *(result+x - 1) = *(result+x - 1) + 1;
    }
}

For this opus entry I am going to try and re-break down what Matt went over with me in the last class session.

The first line of the for loop in the the code block above is stating:

for the instance that the variable x equals the int digit1 and also the variable x is greater than or equal to zero decrement x by 1.

*(result+x) = *(value1+x) + *(value2+x) + *(result+x);

This line is saying that the pointer of result+x is equal to the pointer of value1+x plus the pointer of value2+x plus the pointer of result+x which has been zeroed out for the program.

if(*(result+x) > 9)

The if statement is creating a condition that if the pointer of result+x is greater than the number 9 to go on and do what other instructions are in the if statement.

    {
        *(result+x) = *(result+x) - 10;
        *(result+x - 1) = *(result+x - 1) + 1;
    }

Inside of the if statement as the code shown above is saying process this code when the if statement is true.

Take the current result x variable you are working with and subtract 10 and take the next result x variable to the left and add 1 to it.

Inheritance in object-oriented programming is a way to use code that you have previously included in a class, usually refered to as parent classes, base classes, or a superclasses. The new classes that are inheriting the base class are commonly refered to as child classes or subclasses and or derived classes.

#ifndef _RECTANGLE_H
#define _RECTANGLE_H
#include "shape.h"
 
class rectangle: public shape{
        public:
                virtual int perimeter();
                virtual int area();
};
#endif

As shown in the code block example above this file called rectangle.h would be inheriting the public classes code from the file shape.h making the parent file shape.h and the child file rectangle.h

Class inheritance has three different types of data:

Public:

Any other files in your inheritance tree that include the header files needed to use those public variables of the class you are trying to access can.

Protected:

Only a child file of the parent can use protected files, if a child is not directly pointed to the parent file they are trying to access protected data from that child file will not be able to access the protected portion of that code.

Private:

Private variables are only accessable by the class they are defined in, although they can be accessed through a call to a protected or public variable in the same class that has access.

The GNU Compiler Collection or (GCC) is a programming code compiler, a compiler is an application that uses source code written in a programming language and creates object code to have an executable program from the source code.

The languages the compiler can compile that we deal with in our class are C (gcc) and C++ (g++)

The compiler consists of a front-end and back-end

The front-end of the compiler handles the programming language setting up the information to be handled by the back-end

The back-end deals with converting the language into the specific target architecture

What will happen if you do not include the \n at the end of a printf statement.

lab46

I am thinking that without the \n the printf statement will not display.

State your rationale. I am pretty sure \n is a terminator for the printf statement.

I am going to test my hypothesis on lab46 with my hello.c program.

lab46:~$ nano hello.c
lab46:~$ gcc -o hello hello.c
lab46:~$ ./hello
Hello, World!lab46:~$

Based on the data collected:

• Was your hypothesis correct?

No.

• Was your hypothesis not applicable?

it was applicable.

• Is there more going on than you originally thought? (shortcomings in hypothesis)

No.

• What shortcomings might there be in your experiment?

I guessed wrong.

• What shortcomings might there be in your data?

None.

The program still complied and ran without the \n at the end of my printf statement but as you can see the command prompt ended up on the same line that the program executed the printf on.

So the \n is a line terminator and not a printf function terminator if that makes sense in the best of my ability to explain what I am experimenting.

For this experiment I will be seeing what will happen if the program does not include a main function and just includes statements.

Like this.

#include <stdio.h>
 
{
        printf("Hello, World!\n");
        return(0);
}

Lab46

I am not sure what will happen I am assuming the program will not compile or function properly.

State your rationale.

I am thinking that the program needs a Function structure of some sort to run properly.

going to test this on lab46

lab46:~$ gcc -o hello hello.c
hello.c:3: error: expected identifier or '(' before '{' token

Based on the data collected:

• Was your hypothesis correct?

Yeah I believe this time it was I did get an error for an expected identifier.

• Was your hypothesis not applicable?

it was applicable.

• Is there more going on than you originally thought? (shortcomings in hypothesis)

No I think the identifier the program is looking for is the main function.

• What shortcomings might there be in your experiment?

None.

• What shortcomings might there be in your data?

None.

The program did not compile when the line of

int main()

was removed from the program I am not 100% sure if it was asking for a function container, okay well i just did this experiment to test it further.

#include <stdio.h>
main()
{
        printf("Hello, World!\n");
        return(0);
}

and the program ran and compiled so the int was not necessary it was looking for a main() function or a function container in general I am guessing. Not sure if it has to named main() but that sounds like another experiment.

Perform the following steps:

Whose existing experiment are you going to retest? Provide the URL, note the author, and restate their question.

Evaluate their resources and commentary. Answer the following questions:

• Do you feel the given resources are adequate in providing sufficient background information?
• Are there additional resources you've found that you can add to the resources list?
• Does the original experimenter appear to have obtained a necessary fundamental understanding of the concepts leading up to their stated experiment?
• If you find a deviation in opinion, state why you think this might exist.

State their experiment's hypothesis. Answer the following questions:

• Do you feel their hypothesis is adequate in capturing the essence of what they're trying to discover?
• What improvements could you make to their hypothesis, if any?

Follow the steps given to recreate the original experiment. Answer the following questions:

• Are the instructions correct in successfully achieving the results?
• Is there room for improvement in the experiment instructions/description? What suggestions would you make?
• Would you make any alterations to the structure of the experiment to yield better results? What, and why?

Publish the data you have gained from your performing of the experiment here.

Answer the following:

• Does the data seem in-line with the published data from the original author?
• Can you explain any deviations?
• How about any sources of error?
• Is the stated hypothesis adequate?

Answer the following:

• What conclusions can you make based on performing the experiment?
• Do you feel the experiment was adequate in obtaining a further understanding of a concept?
• Does the original author appear to have gotten some value out of performing the experiment?
• Any suggestions or observations that could improve this particular process (in general, or specifically you, or specifically for the original author).

Wanted to revisit structs and unions from a class we had this semester.

When creating a struct you are making a record for a set of labelled objects into a single structured object.

Example:

struct sales {
    int month sales;
    char *item_name;
    char *item_type;
    float totals;
    };

This is an example of a struct declaration, which is a list of fields that can contain any types (int, char, etc…) and allocates a total amount of storage based on the sum requirements for all of the list types included, along with any internal padding.

A union is nearly the same as a struct except for the way a union allocates memory, each data type in the union starts from the same location in memory instead of having its own location like in a struct.

The concept of a union is to save space the multiple data types inside the union are being condensed into the same memory location.

Example:

union <name>
{
    <datatype>  <1st variable name>;
    <datatype>  <2nd variable name>;
    .
    .
    .
    <datatype>  <nth variable name>;
} <union variable name>;

Since we talked about inheritance at length this semester I will refresh on that with this journal entry.

Inheritance in programing has to do with the way classes relate to each other, for example there are two main types of classes in respect to programming inheritance parent classes and child/children classes.

Parent classes are the preceding classes that came before their children a lot like it would seem. Parent classes are also sometimes called superclasses, ancestor classes or base classes.

Child classes or subclasses are derived from their parent class and live in a hierarchy based system.

The application of using inheritance in programming is to relate two or more classes together.

Figured I would write this opus entry on Header Files since that seems to be one of the thing I do grasp.

There are a few different instances of header files

There is the standard Library of header files which are already made files saved that included commonly used declarations that a program might need, for instance stdio.h which includes common input and output functions used in c programming and stdlib.h which includes standard collection of functions collected into a library file.

There are also header files that you can make on your own for instance if you wrote a function saved it and then included it in another function as a .h file that program will now use all the logic from the other instance your wrote with just the file included at the start of the new file as a .h file.

Just going to scribble some things down here for the last entry as I go through some of the programs we accomplished in class this semester.

int main ( ) anything inside the parenthesis are parameters for main and the first parameter of main must be an integer. when on a line of code if you type a \ followed by enter the syntax is that the line will continue onto the next line below it but the program will read it as a single line of code even though for your viewing pleasure its broken up into more than one line of text. int sum(int, int, int, int); is a function prototype.

and so on…

What will happen if i replace a for loop with a while loop in my program. as shown here

#include<stdio.h>
#include<stdlib.h>
 
int main(int argc, char **argv) //parameters are in the ( ), first parameter of main must be an integer
{
        unsigned char i;
 
        if(argc<2)
        {
                printf("%8s must be run with 1 or\
 more arguments, you only provided %hhu\n",*(argv+0),(argc-1));
                exit(1); // \ followed by enter allows you to continue code on new line
        }
        printf("You ran this program with %hhu arguments, they are:\n",(argc-1));
        for(i=1;i<argc;i++)
        {
                printf("argv[%hhu]: %s\n",i,*(argv+i));
        }
        return(0);
}

I am going to replace the for loop in this program with a while loop and see what happens.

lab46

I do not have a clue what it will do. My best guess is break something.

State your rationale.

Seems like something that would break something.

lab46

lab46:~/src/cprog$ nano sample1.c
lab46:~/src/cprog$ gcc -o sample1 sample1.c
sample1.c: In function 'main':
sample1.c:15: error: expected ')' before ';' token

Based on the data collected:

• Was your hypothesis correct?

Yep it broke

• Was your hypothesis not applicable?

it was

• Is there more going on than you originally thought? (shortcomings in hypothesis)

no I think it just produces a syntax error

• What shortcomings might there be in your experiment?

none

• What shortcomings might there be in your data?

none

I broke the program you can not just simply make a for loop a while loop

I am going to try and add a simple multiplication function to the file sample2.c where we had 4 int declared and the program calculating a sum and average.

lab46

#include<stdio.h>
#include<stdlib.h>
 
int sum(int,int,int,int); //function prototype
int average(int,int,int,int);
int main()
{
        int a,b,c,d;
        int avg;
        a=b=c=d=0;
        avg=0;
        printf("Enter first value: ");
        fscanf(stdin, "%d",&a);
 
        printf("Enter second value: ");
        fscanf(stdin, "%d",&b);
 
        printf("Enter third value: ");
        fscanf(stdin, "%d",&c);
 
        printf("Enter fourth value: ");
        fscanf(stdin, "%d",&d);
 
        fprintf(stdout,"the sum of %d, %d, %d, and %d is:%d\n",a,b,c,d,sum(a,b,c,d));
        fprintf(stdout,"the average of %d, %d, %d, and %d is:%d\n",a,b,c,d,average(a,b,c,d));
        return(0);
}
 
 
int sum(int n1, int n2, int n3, int n4)
{
        int total=0;
        total=n1+n2+n3+n4;
        return(total);
}
int average(int n1, int n2, int n3, int n4)
{
        int average=0;
        average=(n1+n2+n3+n4)/4;
        return(average);
}

I am going to try and follow the code above and add a similar instance for multiplication to see if i can get it to work I assume this will be easier than project 2's concept.

State your rationale. project 2 was dealing with specific allocated 4 digit numbers and something like that i don't know this just looks like it is going to make more sense to me and maybe work.

lab46

lab46:~/src/cprog$ nano sample2.c
lab46:~/src/cprog$ gcc -o sample2 sample2.c
lab46:~/src/cprog$ ./sample2
Enter first value: 2
Enter second value: 2
Enter third value: 2
Enter fourth value: 2
the sum of 2, 2, 2, and 2 is:8
the average of 2, 2, 2, and 2 is:2
the product of 2, 2, 2, and 2 is:16
lab46:~/src/cprog$

Based on the data collected:

• Was your hypothesis correct?

Yeah it worked amazingly.

• Was your hypothesis not applicable?

for once yes.

• Is there more going on than you originally thought? (shortcomings in hypothesis)

no

• What shortcomings might there be in your experiment?

no

• What shortcomings might there be in your data?

no

It worked I am pretty much pro.

Perform the following steps:

Whose existing experiment are you going to retest? Provide the URL, note the author, and restate their question.

Evaluate their resources and commentary. Answer the following questions:

• Do you feel the given resources are adequate in providing sufficient background information?
• Are there additional resources you've found that you can add to the resources list?
• Does the original experimenter appear to have obtained a necessary fundamental understanding of the concepts leading up to their stated experiment?
• If you find a deviation in opinion, state why you think this might exist.

State their experiment's hypothesis. Answer the following questions:

• Do you feel their hypothesis is adequate in capturing the essence of what they're trying to discover?
• What improvements could you make to their hypothesis, if any?

Follow the steps given to recreate the original experiment. Answer the following questions:

• Are the instructions correct in successfully achieving the results?
• Is there room for improvement in the experiment instructions/description? What suggestions would you make?
• Would you make any alterations to the structure of the experiment to yield better results? What, and why?

Publish the data you have gained from your performing of the experiment here.

Answer the following:

• Does the data seem in-line with the published data from the original author?
• Can you explain any deviations?
• How about any sources of error?
• Is the stated hypothesis adequate?

Answer the following:

• What conclusions can you make based on performing the experiment?
• Do you feel the experiment was adequate in obtaining a further understanding of a concept?
• Does the original author appear to have gotten some value out of performing the experiment?
• Any suggestions or observations that could improve this particular process (in general, or specifically you, or specifically for the original author).