else Keyword Usage and Examples

Learn how to use the Java else keyword to handle alternate execution paths. This tutorial covers syntax, examples, common mistakes, and output analysis for beginners.

This reference explains else Keyword Usage and Examples through its syntax, examples and boundaries. Use the linked course lessons when the surrounding Java concepts are unfamiliar.

Use this reference
Identify the documented behavior, read a complete example and check its inputs before applying it.

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.

Using this reference

Check the example’s types, inputs and documented behavior before copying it into an application. Some APIs require external libraries, files or platform services; consult their setup notes.

Supporting documentation: Official Java learning guide.

Reference checks are optional and do not count toward course progress.

Reference library →

else Keyword Usage and Examples