throw vs throws vs Throwable In Java – Explained with Examples

Ramesh Fadatare

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Apr 6, 2025

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In Java exception handling, three commonly confused terms are: throw, throws, and Throwable. At first glance, these keywords and class names may seem related because they all deal with exceptions, but each plays a very different role.

If you’re new to Java or preparing for interviews, it’s essential to understand how throw, throws, and Throwable work — and when to use each one correctly.

In this article, we’ll break down these three concepts with simple language, real code examples, and a comparison table to help you master Java exception handling.

📌 Quick Summary

Let’s now explore each one in detail.

🚀 1. What is throw in Java?

The throw keyword is used in Java to manually throw an exception. You can throw either checked or unchecked exceptions using throw.

Syntax:

throw new ExceptionType("Error message");

Example:

public class ThrowExample {
    public static void main(String[] args) {
        int age = -1;

        if (age < 0) {
            throw new IllegalArgumentException("Age cannot be negative");
        }

        System.out.println("Age is valid");
    }
}

Output:

Exception in thread "main" java.lang.IllegalArgumentException: Age cannot be negative

Key Points:

• You can only throw objects that are instances of Throwable or its subclasses.
• You must throw a new instance of an exception (throw new ...).
• Once throw is executed, the current method is immediately exited.

🚀 2. What is throws in Java?

The throws keyword is used in a method declaration to indicate that the method might throw a checked exception.

This is Java’s way of enforcing compile-time exception checking.