javascript - 如何获取此中的源代码

Question

var a = ["one", "two", "three"];
 console.log(a.indexOf("two")); // output = 1

 a.indexOf = function(val) {
  return 'HAHAHA';
};

console.log(a.indexOf("two")); // output = 'HAHAHA'

有哪些方法可以恢复indexOf的功能？

console.log(a.indexOf("two")); // output = 1

Answer 1

您只需重新分配来自Array.prototype的原始函数即可。 .

var a = ["one", "two", "three"];
 console.log(a.indexOf("two")); // output = 1

a.indexOf = function(val) {
  return 'HAHAHA';
};

console.log(a.indexOf("two")); // output = 'HAHAHA'

a.indexOf = Array.prototype.indexOf; // re-assign the original function
                                     // which is inherited from Array.prototype.

console.log(a.indexOf("two")); // output = 1