Left shift assignment (<<=)

The left shift assignment operator (<<=) moves the specified amount of bits to the left and assigns the result to the variable.


Operator: x <<= y
Meaning:  x   = x << y


Using left shift assignment

let a = 5;
// 00000000000000000000000000000101

bar <<= 2; // 20
// 00000000000000000000000000010100


ECMAScript (ECMA-262)
The definition of 'Assignment operators' in that specification.

Browser compatibility

ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
Left shift assignment (x <<= y)Chrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 3Opera Full support 3Safari Full support 1WebView Android Full support 1Chrome Android Full support 18Firefox Android Full support 4Opera Android Full support 10.1Safari iOS Full support 1Samsung Internet Android Full support 1.0nodejs Full support 0.1.100


Full support
Full support

See also