Overview of Control Flow

Control flow in C refers to the order in which statements are executed in a program. It involves making decisions, repeating actions, and branching based on conditions. Let's explore the fundamental control flow structures in C to gain a better understanding.

1. Sequential Execution

The default control flow in C is sequential execution, where statements are executed in the order they appear in the code.

#include <stdio.h>

int main() {
    // Sequential execution
    printf("Step 1\n");
    printf("Step 2\n");
    printf("Step 3\n");

    return 0;
}

2. Conditional Statements: if, else if, else

Conditional statements allow for decision-making based on conditions.

#include <stdio.h>

int main() {
    int num = 10;

    // Example of if-else statement
    if (num > 0) {
        printf("Positive number\n");
    } else if (num < 0) {
        printf("Negative number\n");
    } else {
        printf("Zero\n");
    }

    return 0;
}

3. Switch Statement

The switch statement is used for multi-way branching based on the value of an expression.

#include <stdio.h>

int main() {
    char grade = 'B';

    // Example of switch statement
    switch (grade) {
        case 'A':
            printf("Excellent\n");
            break;
        case 'B':
            printf("Good\n");
            break;
        case 'C':
            printf("Average\n");
            break;
        default:
            printf("Not defined\n");
    }

    return 0;
}

4. Looping Statements: for, while, do-while

Looping statements allow for repeated execution of a block of code.

Example of for loop:

#include <stdio.h>

int main() {
    // Example of for loop
    for (int i = 1; i <= 5; i++) {
        printf("Iteration %d\n", i);
    }

    return 0;
}

Example of while loop:

#include <stdio.h>

int main() {
    int count = 0;

    // Example of while loop
    while (count < 3) {
        printf("Count: %d\n", count);
        count++;
    }

    return 0;
}

Example of do-while loop:

#include <stdio.h>

int main() {
    int x = 5;

    // Example of do-while loop
    do {
        printf("Value of x: %d\n", x);
        x--;
    } while (x > 0);

    return 0;
}

5. Branching Statements: break, continue, return

Branching statements alter the normal flow of control.

Example of break statement:

#include <stdio.h>

int main() {
    // Example of break statement in a loop
    for (int i = 1; i <= 10; i++) {
        if (i == 5) {
            printf("Breaking the loop at i = 5\n");
            break;
        }
        printf("Iteration %d\n", i);
    }

    return 0;
}

Example of continue statement:

#include <stdio.h>

int main() {
    // Example of continue statement in a loop
    for (int i = 1; i <= 5; i++) {
        if (i == 3) {
            printf("Skipping iteration at i = 3\n");
            continue;
        }
        printf("Iteration %d\n", i);
    }

    return 0;
}

Example of return statement:

#include <stdio.h>

// Example of return statement in a function
int square(int num) {
    return num * num;
}

int main() {
    int result = square(4);
    printf("Square of 4: %d\n", result);

    return 0;
}

Understanding and mastering control flow structures in C is crucial for writing structured and efficient programs. If you have specific questions or if there are additional topics you'd like to explore, feel free to ask. Happy coding!

Last modified: 25 February 2024