Why operators are needed in Java - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add two numbers and print the result.

Java

int a = 5;
int b = 3;
int sum = a [1] b;
System.out.println(sum);

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

A/

B-

C*

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using subtraction or multiplication instead of addition.

The plus operator + adds two numbers together.

2fill in blank

medium

Complete the code to check if a number is greater than 10.

Java

int number = 15;
boolean isGreater = number [1] 10;
System.out.println(isGreater);

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

A>

B<

C==

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using less than or equals instead of greater than.

The greater than operator > checks if the left value is bigger than the right.

3fill in blank

hard

Fix the error in the code to multiply two numbers correctly.

Java

int x = 4;
int y = 6;
int product = x [1] y;
System.out.println(product);

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

A+

B*

C-

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using plus or minus instead of multiplication.

The multiplication operator * multiplies two numbers.

4fill in blank

hard

Fill both blanks to create a condition that checks if a number is between 5 and 10 (inclusive).

Java

int num = 7;
boolean isBetween = num [1] 5 && num [2] 10;
System.out.println(isBetween);

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

A>=

B<

C<=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using only > or < which excludes the boundary numbers.

The operator >= means 'greater than or equal to', and <= means 'less than or equal to'. Together they check if the number is between 5 and 10 inclusive.

5fill in blank

hard

Fill the blanks to create a map of words to their lengths, including only words longer than 3 characters.

Java

Map<String, Integer> lengths = words.stream()
    .filter(word -> word.length() [1] 3)
    .collect(Collectors.toMap(word -> word, word -> word.[2]()));

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

A>

Blength

Dsubstring

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong comparison operators or wrong methods for length.

The filter uses > to keep words longer than 3. The key mapper uses word itself, and the value mapper uses length() to get the word length.