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Today, I’m going to show you how you can implement JUnit tests in Java with a simple example.
The first thing you need to do is to start a Java project and create an example class called Multiplication:
Now let’s create a simple function for multiplication:
public class Multiplication {
}
Next, in this skeleton, let’s implement the JUnit test:
@Test
public void testMultiplication() {
Multiplication multiplication = new Multiplication();
int result = multiplication.multiply(2, 2);
int expected = 4;
assertEquals(expected, result);
}
The test is straightforward. First, we instantiate the Multiplication object we created. Then we perform a multiplication of 2*2 and store the result in a variable. We create a variable to indicate the expected result. We call the JUnit’s assertEquals method to check that the expected result matches the result of the method. And we execute the test:
- Right-click, Run as > JUnit Test
If the test has passed, it will appear in green:
And now, in this skeleton, let’s implement the JUnit test:
@Test
public void testMultiplication() {
Multiplication multiplication = new Multiplication();
int result = multiplication.multiply(2, 2);
int expected = 4;
assertEquals(expected, result);
}
The test is straightforward. First, we instantiate the Multiplication object we created. Then we perform a multiplication of 2*2 and store the result in a variable. We create a variable to indicate the expected result. We call the JUnit’s assertEquals method to check that the expected result matches the result of the method. And we execute the test:
- Right-click, Run as > JUnit Test
If the test has passed, it will appear in green:
