Notes On Basic Structure Of C

                                                                

 C Program Mainly Consist Of:

Preprocessor commands

Functions

Variables

Statement & Expression

Comments

Let's Understand Our Code :

• #include<stdio.h> : It’s a pre-processor command. It means we want to include stdio.h header file in our program. Stdio.h stands for standard input-output. It is a library in C that contains many function definitions such as ‘printf()’, scanf() etc.
•  int main() : main is a function in C language. Execution of every C program starts from main() function. int before main means that the function will return an integer. main function is called by OS.
• {}: Curly braces enclose the body of main() function.
• printf(“Hello World\n”); : print() is a function defined in stdio.h header file and this function displays whatever is written inside its brackets on the screen.
• return 0; : As we know that main function returns an integer value (int main()), therefore we are returning 0 here. return is a keyword which is used to return some value from a function. Returning 0 indicates that our program has been run successfully and we terminate our main function with this return statement.

So, Here Is The Other Program To Add  Two Number :

             

                                           

Now, We'll Understand "How The C program Is Executed" :

 To check all the files which are made during the execution progress of a C program? Type this command in VS Code terminal: gcc –Wall –save-temps (filename.c) –o (desired_filename) and then press enter. After that, all the files which are created during execution progress will be shown up.

Steps Including In Execution Of C Program Are :

Pre-processing -> Compilation -> Assembly -> Linking.

• Pre-Processing: In this process, comments are removed, macros are expanded and #include files are included.

·       Extension of pre-processed file is (.i)

• Compiling: In this process, the pre-processed file is converted into assembly instructions.

·       Extension of assembly instruction file is (.s)

• Assembly: Assembly instructions are then converted into machine language instructions.

·       Extension of machine instruction file is (.o)

• Linking : In this process all object file i.e. (.o) files are converted to executable i.e. (.exe) program.

That’s how the execution of the C program occurs.

Code Written In The Video :

#include <stdio.h>

int main()

{

    int a, b;

    printf("Enter the value of a\n");

    scanf("%d", &a);

    printf("Enter the value of b\n");

    scanf("%d", &b);

    printf("The sum of the numbers is %d", a+b);

    return 0;

}

#include<stdio.h>

int main()

{

   printf("Welcome To Coding Champ");

    return 0;

}