Java else Keyword
Usage and Examples

else Keyword in Java

The else keyword in Java is used to define a block of code that executes when the condition in the associated if statement is false. It gives us a way to provide an alternate path of execution when the primary condition isn’t met.

Syntax of else

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

Simple Example

public class ElseExample {
    public static void main(String[] args) {
        int number = 10;
        if (number < 5) {
            System.out.println("Number is less than 5");
        } else {
            System.out.println("Number is greater than or equal to 5");
        }
    }
}

Number is greater than or equal to 5

Since 10 is not less than 5, the condition in the if block fails. Thus, the else block gets executed.

Using else with User Input

import java.util.Scanner;

public class ElseWithInput {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter your age: ");
        int age = scanner.nextInt();

        if (age >= 18) {
            System.out.println("You are eligible to vote.");
        } else {
            System.out.println("You are not eligible to vote yet.");
        }
    }
}

Sample Output 1

Enter your age: 21
You are eligible to vote.

Sample Output 2

Enter your age: 16
You are not eligible to vote yet.

This shows how else helps to create a fallback condition in real-world scenarios like input validation.

else without if – Is it Valid?

No, else cannot be used independently. It must always be paired with an if block. If used alone, the compiler will throw an error.

// Invalid usage
else {
    System.out.println("This will cause a compilation error");
}

Compilation Error

ElseExample.java:3: error: 'else' without 'if'

Nested if-else with else

We can also use else with nested conditions to create multi-way decision logic.

public class NestedElse {
    public static void main(String[] args) {
        int marks = 75;

        if (marks >= 90) {
            System.out.println("Grade: A");
        } else if (marks >= 75) {
            System.out.println("Grade: B");
        } else if (marks >= 50) {
            System.out.println("Grade: C");
        } else {
            System.out.println("Grade: F");
        }
    }
}

Grade: B

The conditions are evaluated from top to bottom. When marks >= 75 is true, that block executes, and the rest are ignored.

Common Mistakes Using else

• Using else without a corresponding if
• Adding a semicolon after if condition — this can lead to unexpected behavior

// Mistaken semicolon after if
if (value > 0); {
    System.out.println("This block always executes!");
}

Why it’s wrong:

The semicolon ends the if prematurely, so the block below is always executed regardless of the condition.