内容更新于: 2022-09-20 09:09:52
reduce_parseInt
前言:数组的几个问题。[].reduce(Math.pow);输出什么？parseInt
1.reduce
console.log([1,2,3].reduce(Math.pow));
console.log([].reduce(Math.pow));结果:
[console 1]: 1
[console 2]: 报错 Uncaught TypeError: Reduce of empty array with no initial value
2.parseInt
console.log([1,2,3].map(parseInt));结果：
[console 1]: [1, NaN, NaN]
3.typeof & instanceof
console.log(typeof null);
console.log(null instanceof Object);结果：
[console 1]: Object
[console 2]: false
4.getPrototypeOf
function f () {}
const a = f.prototype;
const b = Object.getPrototypeOf(f);
console.log(a === b);结果:
[console 1]: false
本文结束
