Tutorial: Introduction to JavaScript

Operators

arithmetic or computational

Arithmetic operators take numerical values (either literals or variables) as their operands and return a single numerical value. The standard arithmetic operators are:

+	Addition
-	Subtraction
*	Multiplication
/	Division
%	Modulus: the remainder after division; e.g. 10 % 3 yields 1.
++	Unary increment: this operator only takes one operand. The operand's value is increased by 1. The value returned depends on whether the ++ operator is placed before or after the operand; e.g. ++x will return the value of x following the increment whereas x++ will return the value of x prior to the increment.
--	Unary decrement: this operator only takes one operand. The operand's value is decreased by 1. The value returned depends on whether the -- operator is placed before or after the operand; e.g. --x will return the value of x following the decrement whereas x-- will return the value of x prior to the decrement.
-	Unary negation: returns the negation of operand.