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Decrement (--)

The decrement operator (--) decrements (subtracts one from) its operand and returns a value.

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Syntax

x--
--x

Description

If used postfix, with operator after operand (for example, x--), the decrement operator decrements and returns the value before decrementing.

If used prefix, with operator before operand (for example, --x), the decrement operator decrements and returns the value after decrementing.

Examples

Postfix decrement

let x = 3;
y = x--;

// y = 3
// x = 2

Prefix decrement

let a = 2;
b = --a;

// a = 1
// b = 1

Specifications

Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet Deno Node.js
Decrement
2
12
1
3
3
4
4.4
18
4
10.1
3.2
1.0
1.0
0.10.0

See also

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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Decrement