Problem Solving Through C (BCA) 1st Sem Previous Year Solved Question Paper 2022

The structure of a C program typically consists of various components, including comments, preprocessor directives, function declarations, and the main function. Let me illustrate this with a simple example program:

#include <stdio.h> // Preprocessor directive

// Function declaration

int add(int a, int b);

int main() {

// Variables

int num1, num2, sum;

// Input

printf("Enter two numbers: ");

scanf("%d %d", &num1, &num2);

// Function call

sum = add(num1, num2);

// Output

printf("Sum: %d\n", sum);

return 0; // Return statement

}

// Function definition

int add(int a, int b) {

return a + b;

}

1. Comments:

   • Comments provide human-readable explanations within the code.

   • In the example, ‘//’ is used for single-line comments, and ‘/* */’ is used for multi-line comments.

2. Preprocessor Directives:

   • These are instructions to the preprocessor that modify the source code before actual compilation.

   • #include <stdio.h> is a common directive to include the standard input/output library.

3. Function Declaration:

   • Function declarations specify the function's name, return type, and parameter types.

   • In the example, ‘int add(int a, int b); ‘declares the’add’ function.

4. main() Function:

   • The main() function is the entry point of the program.

   • It contains the program's logic.

   • It returns an integer value (usually 0) to indicate the program's status.

5. Variables:

   • Variables are used to store and manipulate data.

   • In the example, ‘num1’, ‘num2’, and ‘sum’ are declared as integer variables.

6. Input and Output:

   • ‘ Printf ’ is used to display output to the console.

   • ‘ Scanf ’ is used to read input from the user.

7. Function Definition:

   • The ‘add’ function is defined after the ‘main’ function. It takes two integer parameters and returns their sum.

8. Return Statement:

   • The ‘return 0; statement in the ‘main’ function indicates that the program executed successfully.

This structure provides a basic framework for C programs. The program starts with the ‘main()’ function, which is where execution begins. Functions are used to modularize code and improve readability and reusability.