JS隐式转换一道面试题
温故而知新
const a = {};
const b = {key: 'b'};
const c = {key: 'c'}:
a[b] = 123;
a[c] = 456;
console.log(a[b]);
结果打印为 456
原因,对象属性只能是字符串类型,a[b]
时会把b对象toString === "[object Object]"
所以在a[b] === a[c] === a["[object Object]"]
, 所以最后输出为 456