Operator precedence in Javascript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is operator precedence in JavaScript?

Operator precedence determines the order in which operators are evaluated in an expression. Operators with higher precedence are evaluated before those with lower precedence.

beginner

Which operator has higher precedence: multiplication (*) or addition (+)?

Multiplication (*) has higher precedence than addition (+), so it is evaluated first in an expression.

beginner

How does parentheses affect operator precedence?

Parentheses have the highest precedence and force the expression inside them to be evaluated first, regardless of other operators.

beginner

What is the result of the expression: 3 + 4 * 2?

The multiplication happens first: 4 * 2 = 8. Then addition: 3 + 8 = 11. So, the result is 11.

beginner

True or False: The assignment operator (=) has higher precedence than addition (+).

False. The addition operator (+) has higher precedence than the assignment operator (=). So addition happens before assignment.

Which operator is evaluated first in the expression: 5 + 3 * 2?

A Multiplication (*)

B Addition (+)

C Left to right

D Assignment (=)

Multiplication (*) has higher precedence than addition (+), so it is evaluated first.

What does parentheses do in an expression?

A They lower operator precedence

B They force evaluation inside them first

C They change operator types

D They have no effect

Parentheses have the highest precedence and force the expression inside to be evaluated first.

Which operator has the lowest precedence?

A Multiplication (*)

B Addition (+)

C Assignment (=)

D Exponentiation (**)

Assignment (=) has lower precedence than arithmetic operators like +, *, and **.

What is the result of: (2 + 3) * 4?

A 5

B 14

C 24

D 20

Parentheses evaluated first: 2 + 3 = 5, then multiplied by 4 = 20.

In the expression 10 - 4 + 2, which operator is evaluated first?

A Subtraction (-)

B Addition (+)

C Both at the same time

D Depends on parentheses

Subtraction and addition have the same precedence and are evaluated left to right, so subtraction happens first.

Explain how operator precedence affects the evaluation of the expression 8 + 2 * 5.

Think about which operation happens first without parentheses.

Describe the role of parentheses in changing the order of operations in JavaScript expressions.

Consider how parentheses can change 2 + 3 * 4 to (2 + 3) * 4.