JavaScript Operator Precedence

Operator precedence describes the order of execution of operations in arithmetic expressions.

The precedence of multiplication (*) and division (/) is higher than that of addition (+) and subtraction (-).

Example

As with traditional mathematics, multiplication is performed first:

let x = 100 + 50 * 3;

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When using parentheses, the operations within the parentheses are calculated first:

let x = (100 + 50) * 3;

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Operations with the same precedence (such as * and /) are calculated from left to right:

let x = 100 / 50 * 3;

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Operator precedence values

Expressions within parentheses are evaluated before the rest of the expression, and functions are executed before the result is used in the rest of the expression:

Precedence Operator Description Example
18 ( ) Expression grouping (100 + 50) * 3
myFunction() . [] .
myFunction() person.name [] Property membership
myFunction() person["name"] ?. ES2020 Optional chaining
myFunction() x ?. y () Function call
myFunction() 16 17 New with parameters
new Date("June 5,2022") 16 new New without parameters

new Date()

Increment operators
i++ ++ Postfix increment is executed before prefix increment. Postfix increment
i++ -- 15 i--
14 ++ Prefix increment ++i
14 -- Prefix decrement --i

NOT operator
14 ! Logical NOT !(x==y)
14 ~ Bitwise NOT ~x

Unary operators
14 + Unary plus +x
14 - Unary minus -x
14 typeof Data type typeof x
14 void Evaluate empty void(0)
14 delete Property deletion delete myCar.color

Arithmetic operators

Exponential operation is executed before multiplication.

Multiplication and division are executed before addition and subtraction.
13 ** Exponential operation ES2016 10 ** 2
12 * Multiplication 10 * 5
12 / Division 10 / 5
12 % Division remainder 10 % 5
11 + Addition 10 + 5
11 - Subtraction 10 - 5
11 + Concatenation "Bill" + "Gates"

Shift operators
10 << Left shift x << 2
10 >> Right shift (signed) x >> 2
10 >>> Right shift (unsigned) x >>> 2

Relational operators
9 in Property in object "PI" in Math
9 instanceof Object instance x instanceof Array

Comparison operators
9 < Less than x < y
9 <= Less than or equal to x <= y
9 > Greater than x > y
9 >= Greater than or equal to x >= Array
8 == Equal to x == y
8 === Strict equality x === y
8 != Inequality x != y
8 !== Strict inequality x !== y

Bitwise operators
7 & Bitwise AND x & y
6 ^ Bitwise XOR x ^ y
5 | Bitwise OR x | y

Logical operators
4 && Logical AND x && y
3 || Logical OR x || y
3 ?? Nullish coalescing ES2020 x ?? y

Conditional (ternary) operator
2 ? : Conditional ? "yes" : "no"

Assignment Operator

Assignment is executed after other operations.
2 = Simple Assignment x = y
2 : Colon Assignment x: 5
2 += Addition Assignment x += y
2 -= Subtraction Assignment x -= y
2 *= Multiplication Assignment x *= y
2 **= Exponent Assignment x **= y
2 /= Division Assignment x /= y
2 %= Modulo Assignment x %= y
2 <<= Left Shift Assignment x <<= y
2 >>= Right Shift Assignment x >>= y
2 >>>= Unsigned Right Shift x >>>= y
2 &= Bitwise AND Assignment x &= y
2 |= Bitwise OR Assignment x |= y
2 ^= Bitwise XOR Assignment x ^= y
2 &&= Logical AND Assignment x &= y
2 ||= Logical OR Assignment x ||= y
2 => Arrow x => y
2 yield Pause / Resume yield x
2 yield* Delegation Operator yield* x
2 ... Spread Operator ... x
1 , Comma x, y

See Also

Tutorial:JavaScript Operators

Reference Manual:JavaScript Operators