JS: Operators | JavaScript | Tutorials by PiTribe

JavaScript Operators

var sum = 1 + 2;

The variable, identifier, constant or number used in the operation is called operand (e.g. 1 and 2)
The symbol performing operation is called operator (e.g. +)

Operator is a symbol that performs a particular operation.

JavaScript operators are following types:

Arithmetic operators
Assignment operators
Logical operators
Comparision operators
Bitwise operators

In this chapter consider x = 1, y = 2 and z = 3 for upcoming examples

JavaScript Arithmetic operators

JavaScript arithmetic operators perform an arithmetic (mathematical or algebric) operation. Following are the JavaScript arithmetic operators in order of their precedence.

JavaScript Assignment operators

JavaScript Comparision operators

JavaScript Comparision operators perform a comparision operation.

JavaScript == equal operator

JavaScript == operator compares either two operands are equal.

JavaScript === operator

JavaScript != operator

JavaScript !== operator

JavaScript < operator

JavaScript > operator

JavaScript >= operator

JavaScript <= operator

JavaScript Comparision operators truth table

Operator	Example	Result
==	x == "1"	true
===	x === "1"	false
!=	x != "1"	false
!==	x !== "1"	true
>	x > 1	false
<	x < 1	false
>=	x >= 1	true
<=	x <= 1	true

JavaScript Logical operators


var x=1, y=2;
if(x > y)
	console.log('Greater');
else if(x < y)
	console.log('Smaller');
else
	console.log('Equal');

JavaScript Logical or Relational operators compare logical results.

JavaScript ! NOT operator

JavaScript || OR operator

JavaScript && AND operator

JavaScript Bitwise operators

JavaScript bitwise operators perform an the respective operation on 32-bit numbers . Following are the JavaScript arithmetic operators in order of their precedence.

JavaScript Ternary Operator

The ternary (or conditional) operator is the alternate of if, works as a single statement. var s = x > y ? 'Greater' : x < y :'Smaller' : 'Equal'; console.log(s); JavaScript Ternary operator is the only operator require three operands:

Condition (just like in if-else statement)
Expression when condition is true
Expression when condition is false (just like else statement)

Following are the properties of Ternary conditional operator:

Takes three arguments
Condition applied in a single statment
Allows nested conditions
Allows single statment for true & false conditions, not block unlike if else condition.

JavaScript operators precedence

Operators precedence means which operator will be computed first among other operators. Operator precedence can said as the operator priority given by JavaScript. Following is the table of JavaScript operators according to their precedence, high to low.

Operator	Name	Association	Example
()	Parenthesis Grouping	a*(c+d)
.	Object member access	left-to-right	arr.length
[]	Computed Member Access	left-to-right	arr[0]
new	object creation and constructor arguments	not-applicable	new Array(5,23,680)
()	Function call	left-to-right	parseInt("3")
new	object creation with empry constructor	right-to-left	new Array()
++,--	Postfix Increment, Postfix Decrement	not-applicable	x++,y--
! ~ + - ++ -- typeof void delete	Logical NOT, Bitwise NOT, Unary Plus, Unary Nevation, Prefix Increment, Prefix Decrement, typeof statement, void keyword, delete statement	right-to-left	!++x>--y
**	Exponentiation (exponent/power)	right-to-left
%	Remainder/Modulus	left-to-right
* /	Product (Multiply/Divide)	left-to-right
+ -	Sum (Plus/Minus)	left-to-right
<< >> >>>	Bitwise Shift
< <= > >= in instanceof	Relational Operators, in keyword, instanceof keyword	left-to-right
== != === !==	Equality, Inequality, Strict Equality and Strict Inequality Operators	left-to-right
&	Bitwise AND	left-to-right
^	Bitwise XOR	left-to-right
\|	Bitwise OR	left-to-right
&&	Logical AND	left-to-right
\|\|	Logical OR	left-to-right
?:	Ternary operator	right-to-left	x == y ? "equal" : "different"
= += -= = /= %= *= <<= >>= >>>= &= ^= \|=	Assignment	right-to-left	z = ++x % y--
yield	Yield	right-to-left	yield x
Spread	not-applicable
,	Comma	left-to-right	var x = 3,y = x + 1, z = ++y

An operator with higher precedence (e.g. *) is computed before the low precedence operator (e.g. +).


var x = 1, y = 2, z=3;
var ans = x + y * z;
console.log(ans);

7

There are two operators, + & *. Since * has higher precedence over +, that's y is multiplied by z (result:6) and then x is added to their result (1 + 6).

Let's make a small change, add () operator.


var x = 1, y = 2, z=3;
var ans = (x + y) * z;
console.log(ans);

9

Since () has higher prcedence than * and +, that's x is added to y as they are inside the parenthesis () (result:3). Then the result is multiplied by z (3 * 3).

Notes

Ternary operator ?: is the single statement conditional operator alternate to if else
Operators are computed with respect to the operator precedence.