JavaScript Arithmetic

JavaScript Arithmetic Operators

Arithmetic operators perform arithmetic on numbers (literals or variables).

Arithmetic Operations

A typical arithmetic operation operates on two numbers.

The two numbers can be literals:

or variables:

or expressions:

Operators and Operands

The numbers (in an arithmetic operation) are called operands.

The operation (to be performed between the two operands) is defined by an operator.

Adding

The addition operator (+) adds numbers:

Subtracting

The subtraction operator (-) subtracts numbers.

Multiplying

The multiplication operator (*) multiplies numbers.

Dividing

The division operator (/) divides numbers.

Remainder

The modulus operator (%) returns the division remainder.

Incrementing

The increment operator (++) increments numbers.

Decrementing

The decrement operator (--) decrements numbers.

Exponentiation

The exponentiation operator (**) raises the first operand to the power of the second operand.

x ** y produces the same result as Math.pow(x,y):

Operator Precedence

Operator precedence describes the order in which operations are performed in an arithmetic expression.

Is the result of example above the same as 150 * 3, or is it the same as 100 + 150?

Is the addition or the multiplication done first?

As in traditional school mathematics, the multiplication is done first.

Multiplication (*) and division (/) have higher precedence than addition (+) and subtraction (-).

And (as in school mathematics) the precedence can be changed by using parentheses.

When using parentheses, the operations inside the parentheses are computed first:

When many operations have the same precedence (like addition and subtraction or multiplication and division), they are computed from left to right:

alert(10  2);