求幂赋值 (**=)

¥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

¥Exponentiation assignment using numbers

let bar = 5;
bar **= 2; // 25

其他非 BigInt 值被强制转换为数字：

¥Other non-BigInt values are coerced to numbers:

let baz = 5;
baz **= "foo"; // NaN

¥Exponentiation assignment using BigInts

let foo = 3n;
foo **= 2n; // 9n
foo **= 1; // TypeError: Cannot mix BigInt and other types, use explicit conversions

¥See also

• JS 指南中的赋值运算符
• 求幂 (**)