Operator precedence in Java - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to correctly calculate the result using operator precedence.

Java

int result = 5 + 3 [1] 2;

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

A*

B+

C-

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of * causes the addition to happen first, changing the result.

The multiplication operator (*) has higher precedence than addition, so 3 * 2 is calculated first, then added to 5.

2fill in blank

medium

Complete the code to correctly evaluate the expression considering operator precedence.

Java

int value = 10 - 4 [1] 2;

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

A*

B+

C-

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of * changes the operation order and result.

The multiplication operator (*) has higher precedence than subtraction, so 4 * 2 is calculated first, then subtracted from 10.

3fill in blank

hard

Fix the error in the expression to respect operator precedence and get the correct result.

Java

int output = 20 / 4 [1] 2;

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

A/

B*

C+

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using * or / again changes the order and result unexpectedly.

Division and multiplication have the same precedence and are evaluated left to right. Using subtraction (-) after division changes the result correctly.

4fill in blank

hard

Fill both blanks to create a map of numbers to their doubled values only if the number is greater than 3.

Java

Map<Integer, Integer> squares = IntStream.range(1, 6)
    .filter(n -> n [1] 3)
    .boxed()
    .collect(Collectors.toMap(n -> n, n -> n [2] 2));

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

A>

B*

C<

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of > in filter selects wrong numbers.

Using + instead of * does addition, not doubling.

The filter uses > to select numbers greater than 3. The map doubles each number using the * operator.

5fill in blank

hard

Fill all three blanks to create a map of uppercase strings to their lengths only if the length is greater than 4.

Java

Map<String, Integer> result = words.stream()
    .filter(word -> word.length() [1] 4)
    .collect(Collectors.toMap(word -> word.[2](), word -> word.[3]()));

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

A<

Blength

C>

DtoUpperCase

Attempts:

3 left

💡 Hint

Common Mistakes

Using < instead of > in filter.

Using length instead of toUpperCase for keys.

Using toUpperCase instead of length for values.

The filter uses > to select words longer than 4 characters. The map uses toUpperCase() for keys and length() for values.