Operator precedence in JavaScript

Operator precedence refers to the priority given to operators while parsing a statement that has more than one operator performing operations in it. Operators with higher priorities are resolved first. But as one goes down the list, the priority decreases and hence their resolution.

( * ) and ( / ) have higher precedence than ( + ) and ( - )

Precedence and Associativity

The associativity represents which operator has to solve first while going from left to right if two or more operators have the same precedence in the expression.

Example:

2 + 3 * 4 / 3 =  2 + (3 * 4) / 3  // 6

The precedence of the multiply(*) and divide(/) operators is the same but due to associativity from left to right the multiply operator will be resolved first as it comes first when we go from left to right and hence the result will be 6.

Operator Precedence and Associativity Table

The operator precedence and associativity table can help one know the precedence of an operator relative to other operators. As one goes down the table, the precedence of these operators decreases over each other. The operators as subparts of precedence will have the same specified precedence and associativity as contained by the main part.

Precedence	Operator	Description	Associativity	Example
1	()	Grouping	–	(1+2)
2	.	Member	left to right	obj.function
2.1	[]	Member	left to right	brand[“carName”]
2.2	new	Create		new Date(“July 27, 2023”)
2.3	()	Function Call		myFun()
3	++	Postfix increment	N/A	i++
3.1	—	Postfix Decrement	N/A	i–
4	++	Prefix increment	right to left	++i
4.1	—	Prefix Decrement	N/A	–i
4.2	!	Logical NOT	N/A	!(x===y)
4.3	typeof	Type	N/A	typeof a
5	**	Exponentiation	right to left	4**2
6	*	Multiplication	left to right	2*3
6.1	/	Division		18/9
6.2	%	Remainder		4%2
7	+	Addition	left to right	2+4
7.1	–	Subtraction		4-2
8	<<	Left shift	left to right	y<<2
8.1	>>	Right Shift		y>>2
8.2	>>>	Unsigned right shift		y>>>2
9	<	Less than	left to right	3<4
9.1	<=	Less than or equal to		3<=4
9.2	>	Greater than		4>3
9.3	>=	Greater than or equal to	4>=3
9.4	In	In		“PI” in MATH
9.5	Instance of	Instance of		A instanceof B
10	==	Equality	left to right	x==y
10.1	!=	Inequality		x!=y
10.2	===	Strictly equal		x===y
10.3	!==	Strictly unequal		x!==y
11	&	Bitwise AND	left to right	x&y
12	^	Bitwise XOR	left to right	x^y
13	|	Bitwise OR	left to right	x|y
14	&&	Logical AND	left to right	x&&y
15	||	Logical OR	left to right	x||y
16	? :	Conditional	right to left	(x>y)?x:y
17	=	Assignment	right to left	x=5
17.1	+=	Addition assignment		x+=5 // x=x+5
17.2	-=	Subtraction assignment		x-=5 // x=x-5
17.3	*=	Multiplication assignment		x*=5 // x = x*5
17.4	/=	Division assignment		x/=5 // x = x/5
17.5	%=	Modulo assignment		x%=5 // x = x%5
17.6	<<=	left shift assignment		x<<=5 // x=x<<5
17.7	>>=	right shift assignment		x>>=5 // x=x>>5
17.8	>>>=	Unsigned right shift assignment		x>>>=5 // x=x>>>5
17.9	&=	Bitwise AND assignment		x&=5 // x=x&5
17.10	^=	Bitwise XOR assignment		x^=5 // x=x^5
17.11	|=	Bitwise OR assignment		x|=5 // x=x|5
18	yield	Pause function	right to left	yield x
19	,	Comma	left to right	x,y