C If-Else Statement

🔀 C If-Else Statement – Conditional Logic Explained

The if-else statement in C is used to perform different actions based on different conditions. It’s like giving your program a choice: “If this is true, do this, otherwise do that.”

🔹 Basic Syntax of if-else

if (condition) {
    // Code if condition is true
} else {
    // Code if condition is false
}

📝 Example: Basic If-Else

This example checks if a number is positive or negative.

#include <stdio.h>

int main() {
    int number = -10;

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

    return 0;
}
  

📝 Example: If-Else with User Input

This program asks the user to enter a number and then decides if it’s even or odd.

#include <stdio.h>

int main() {
    int num;
    printf("Enter a number: ");
    scanf("%d", &num);

    if (num % 2 == 0) {
        printf("The number is even.\n");
    } else {
        printf("The number is odd.\n");
    }

    return 0;
}
  

🔹 Nested If-Else

You can put one if-else inside another to make more complex decisions.

📝 Example: Nested If-Else

This checks if a number is positive, negative, or zero.

#include <stdio.h>

int main() {
    int number = 0;

    if (number > 0) {
        printf("Positive number.\n");
    } else {
        if (number < 0) {
            printf("Negative number.\n");
        } else {
            printf("It's zero!\n");
        }
    }

    return 0;
}
  

🎯 Quick Tips

• if checks a condition.
• else runs if the condition is false.
• Conditions use comparison operators like ==, >, <, !=, etc.
• You can nest multiple if-else blocks for detailed logic.

🎉 Try It Yourself!

Modify the examples with your own numbers and conditions. Observe how the flow changes. Logic is fun when you play with it!