Argument conversion in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to convert the string argument to an integer in the test method.

JUnit

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class ConversionTest {
    @Test
    void testStringToInt() {
        String input = "123";
        int number = Integer.[1](input);
        assertEquals(123, number);
    }
}

Drag options to blanks, or click blank then click option'

AparseInt

BvalueOf

CtoString

DintValue

Attempts:

3 left

💡 Hint

Common Mistakes

Using valueOf returns an Integer object, not a primitive int.

Using toString is for converting to String, not from String.

intValue is a method on Integer objects, not static.

The method Integer.parseInt converts a String to a primitive int, which is needed here for the assertion.

2fill in blank

medium

Complete the code to convert the string argument to a double in the test method.

JUnit

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class ConversionTest {
    @Test
    void testStringToDouble() {
        String input = "3.14";
        double value = Double.[1](input);
        assertEquals(3.14, value);
    }
}

Drag options to blanks, or click blank then click option'

AdoubleValue

BvalueOf

CtoString

DparseDouble

Attempts:

3 left

💡 Hint

Common Mistakes

Using valueOf returns a Double object, not a primitive double.

toString is unrelated to conversion from String.

doubleValue is an instance method, not static.

Double.parseDouble converts a String to a primitive double, which matches the variable type.

3fill in blank

hard

Fix the error in the code to correctly convert the string argument to a boolean.

JUnit

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class ConversionTest {
    @Test
    void testStringToBoolean() {
        String input = "true";
        boolean flag = Boolean.[1](input);
        assertTrue(flag);
    }
}

Drag options to blanks, or click blank then click option'

AparseBoolean

BvalueOf

CbooleanValue

DtoString

Attempts:

3 left

💡 Hint

Common Mistakes

Using valueOf returns a Boolean object, not primitive boolean.

booleanValue is an instance method, not static.

toString converts to String, not from String.

Boolean.parseBoolean converts a String to a primitive boolean, which is needed here for assertTrue.

4fill in blank

hard

Fill both blanks to convert a string to an Integer object and then get its int value.

JUnit

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class ConversionTest {
    @Test
    void testStringToIntValue() {
        String input = "456";
        Integer obj = Integer.[1](input);
        int number = obj.[2]();
        assertEquals(456, number);
    }
}

Drag options to blanks, or click blank then click option'

AvalueOf

BparseInt

CintValue

DtoString

Attempts:

3 left

💡 Hint

Common Mistakes

Using parseInt returns primitive int, not Integer object.

Using toString is unrelated to conversion.

Using parseInt then calling intValue causes error because int is primitive.

Integer.valueOf converts String to Integer object; intValue gets primitive int from Integer.

5fill in blank

hard

Fill all three blanks to convert a string to a Double object, get its double value, and assert equality.

JUnit

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class ConversionTest {
    @Test
    void testStringToDoubleValue() {
        String input = "9.81";
        Double obj = Double.[1](input);
        double value = obj.[2]();
        assertEquals([3], value);
    }
}

Drag options to blanks, or click blank then click option'

AvalueOf

BdoubleValue

C9.81

DparseDouble

Attempts:

3 left

💡 Hint

Common Mistakes

Using parseDouble returns primitive double, not Double object.

Using toString is unrelated.

Using wrong literal in assertEquals causes test failure.

Double.valueOf converts String to Double object; doubleValue gets primitive double; assertEquals compares with 9.81.