左移赋值 (<<=)

左移赋值 (<<=) 运算符对两个操作数执行左移，并将结果赋给左操作数。

¥The left shift assignment (<<=) operator performs left shift on the two operands and assigns the result to the left operand.

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¥Syntax

x <<= y

¥Description

x <<= y 与 x = x << y 等效，只是表达式 x 仅计算一次。

¥x <<= y is equivalent to x = x << y, except that the expression x is only evaluated once.

¥Examples

¥Using left shift assignment

let a = 5;
// 00000000000000000000000000000101

a <<= 2; // 20
// 00000000000000000000000000010100

let b = 5n;
b <<= 2n; // 20n

Specification
ECMAScript Language Specification # sec-assignment-operators

¥Specifications

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¥Browser compatibility

¥See also