CsvSource: Digits
You've revisited the lastDigit() from Chapter 1, and this time you've prepared for negative values using Math.abs(). Now that you know you can condense tests using @ParameterizedTest, you've attempted to test all outcomes of lastDigit() in one go.
Verify the method returns the correct digit for positive, negative, and zero-ending integers.
This exercise is part of the course
Introduction to Testing in Java
Exercise instructions
- Use the annotation for inputting multiple values into a test method.
- Add the method arguments for the test method.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.*;
import static com.datacamp.util.testing.CustomJUnitTestLauncher.launchTestsAndPrint;
import static org.junit.jupiter.api.Assertions.*;
public class LastDigitWithTests {
public static void main(String[] args) {
launchTestsAndPrint(LastDigitTest.class);
}
}
class LastDigit {
public static int lastDigit(int a) {
return Math.abs(a) % 10;
}
}
class LastDigitTest {
@ParameterizedTest
// Use the correct annotation for a pair of integer inputs
____(value = {"2025, 5", "-2025, 5", "2020, 0"})
// Write the corresponding argument types for the test method
void testLastDigit(____ number, ____ expected) {
int actual = LastDigit.lastDigit(number);
assertEquals(expected, actual);
}
}