C Control Flow (if, switch) Tutorial

1. Using the if Statement

The if statement allows your program to execute code conditionally:

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#include <stdio.h>

int main() {
    int number = 10;

    if (number > 0) {
        printf("The number is positive.\\n");
    }

    return 0;
}

This program checks if number is greater than zero and prints a message if the condition is true.

2. Adding an else Block

Use else to specify an alternative block of code to execute if the condition is false:

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#include <stdio.h>

int main() {
    int number = -5;

    if (number > 0) {
        printf("The number is positive.\\n");
    } else {
        printf("The number is not positive.\\n");
    }

    return 0;
}

3. Using the switch Statement

The switch statement is used for multiple conditions based on the value of a variable:

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#include <stdio.h>

int main() {
    int day = 2;

    switch (day) {
        case 1:
            printf("Monday\\n");
            break;
        case 2:
            printf("Tuesday\\n");
            break;
        case 3:
            printf("Wednesday\\n");
            break;
        default:
            printf("Other day\\n");
    }

    return 0;
}

This program uses switch to print the name of a day based on its number.

4. Tips and Best Practices

• Always include a default case in switch for unexpected values.
• Use break in switch cases to avoid fall-through behavior.
• Keep conditions simple and readable.

5. Conclusion

Control flow statements like if, else, and switch are essential tools in C programming. Practice using them to make your programs dynamic and responsive.