call
Function.prototype.mycall = function(context, ...args) {
if (this === Function.prototype) {
return undefined;
}
context = context || window;
const fn = Symbol();
context[fn] = this; // this就是 调用的函数
const result = context[fn](...args); //
delete context[fn];
return result;
}
实现逻辑如下，把函数给这个对象，然后通过对象的方式调用，this 就指向这个 对象了
function test(...args) {
console.log(this.name, ...args);
}
let obj = {
name: 'lisi'
}
obj.fn = test;
obj.fn(1,2);
apply 只是参数处理不一样
Function.prototype.myapply = function(context, args) {
if (this === Function.prototype) {
return undefined;
}
context = context || window;
const fn = Symbol();
context[fn] = this; // this就是 调用的函数
const result = context[fn](...args); //
delete context[fn];
return result;
}
标签：Function,...,args,applay,call,result,context,手写,fn From： https://www.cnblogs.com/bruce-gou/p/17273261.html