More on JavaScript Operators

Read this article to learn more about using operators in JavaScript. We will not use all of them in this introductory course. However, this is a condensed reference that contains tables of all operator categories. JavaScript categorizes operators by the task (such as arithmetic, comparison, or assignment). Operators execute in a particular order. This is called operator precedence and tells JavaScript which part to evaluate first, second, third, and so on. This is an important concept.

For example, consider how a program calculates a price using arithmetic operators:

Multiplication first the result is: $18 = 4 + 2 * 7 ( 2 * 7 = 14 + 4)
Calculate left to right the result is: $42 = 4 + 2 * 7 (4+ 2 = 6 * 7)

Arithmetic operators

An arithmetic operator takes numerical values (either literals or variables) as their operands and returns a single numerical value. The standard arithmetic operators are addition (+), subtraction (-), multiplication (*), and division (/). These operators work as they do in most other programming languages when used with floating point numbers (in particular, note that division by zero produces Infinity). For example:

1 / 2; // 0.5
1 / 2 == 1.0 / 2.0; // this is true

In addition to the standard arithmetic operations (+, -, *, /), JavaScript provides the arithmetic operators listed in the following table:

Arithmetic operators

Operator	Description	Example
Remainder (`%`)	Binary operator. Returns the integer remainder of dividing the two operands.	12 % 5 returns 2.
Increment (`++`)	Unary operator. Adds one to its operand. If used as a prefix operator (`++x`), returns the value of its operand after adding one; if used as a postfix operator (`x++`), returns the value of its operand before adding one.	If `x` is 3, then `++x` sets `x` to 4 and returns 4, whereas `x++` returns 3 and, only then, sets `x` to 4.
Decrement (`--`)	Unary operator. Subtracts one from its operand. The return value is analogous to that for the increment operator.	If `x` is 3, then `--x` sets `x` to 2 and returns 2, whereas `x--` returns 3 and, only then, sets `x` to 2.
Unary negation (`-`)	Unary operator. Returns the negation of its operand.	If `x` is 3, then `-x` returns -3.
Unary plus (`+`)	Unary operator. Attempts to convert the operand to a number, if it is not already.	`+"3"` returns `3`. `+true` returns `1`.
Exponentiation operator (`**`)	Calculates the `base` to the `exponent` power, that is, `base^exponent`	`2 3` returns `8`. `10 -1` returns `0.1`.