If–Else If Chains

What Are If–Else If Chains?

An if–else if chain lets you check several conditions, one after another. You use this when you need your program to make decisions based on more than two possible situations. Kotlin checks each condition in order and runs the code for the first one that is true.

Basic Structure

Here is the general structure of an if–else if chain in Kotlin:

if (condition1) {
    // Code runs if condition1 is true
} else if (condition2) {
    // Code runs if condition2 is true
} else {
    // Code runs if none of the above conditions are true
}

You can have as many else if branches as you need. The else branch is optional, but it is useful for handling all the remaining cases.

How It Works

• Kotlin checks the first condition;
• If it is false, Kotlin checks the next else if condition;
• This continues until a condition is true, then only that block runs;
• If none are true, the else block runs (if it exists).

Example: Grading System

Suppose you want to assign a letter grade based on a student's score:

package com.example

fun main() {
    val score = 76
    if (score >= 90) {
        println("Grade: A")
    } else if (score >= 80) {
        println("Grade: B")
    } else if (score >= 70) {
        println("Grade: C")
    } else if (score >= 60) {
        println("Grade: D")
    } else {
        println("Grade: F")
    }
}

In this example:

• If the score is 90 or above, the program prints Grade: A;
• If the score is 80 or above (but less than 90), it prints Grade: B;
• If the score is 70 or above (but less than 80), it prints Grade: C;
• If the score is 60 or above (but less than 70), it prints Grade: D;
• If none of these are true, it prints Grade: F.

When to Use If–Else If Chains

• When you need to check multiple, exclusive conditions;
• When each outcome should be handled differently;
• When the order of conditions matters for your logic.

If–else if chains are a clear and simple way to handle decision-making in your Kotlin programs.