How do I write tests using JUnit?

How do I write tests using JUnit?

To write tests using JUnit, you need to create a test class and annotate your test methods with @Test.

Can you show me a simple example?

Sure! Here's a basic example:

import org.junit.Test;
import static org.junit.Assert.*;

public class SimpleTest {
    @Test
    public void testAddition() {
        assertEquals(2, 1 + 1);
    }
}

What if I want to test for exceptions?

You can use the @Test(expected = Exception.class) annotation to test for exceptions. For example:

@Test(expected = ArithmeticException.class)
public void testDivisionByZero() {
    int result = 1 / 0;
}

How do I run these tests?

You can run JUnit tests using your IDE's built-in test runner or by using Maven/Gradle commands in the terminal.