手寫 call apply bind
阿新 • • 發佈：2022-05-10
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <title>call&apply&bind</title> </head> <body> <script> // 將方法掛載到物件上 // 執行物件的方法 // 將這個方法從物件上移除 Function.prototype.myCall = function (context, ...args) { let fn = Symbol(1); context[fn] = this; context[fn](...args); Reflect.deleteProperty(context, 'fn'); }; Function.prototype.myApply= function (context, args = []) { let fn = Symbol(1); if (args && !(args instanceof Array)) { throw 'error'; } context[fn] = this; context[fn](...args); Reflect.deleteProperty(context, 'fn'); }; Function.prototype.myBind =function (context, ...args) { return (...args2) => { let fn = Symbol(1); context[fn] = this; context[fn](...args.concat(...args2)); Reflect.deleteProperty(context, 'fn'); }; }; </script> </body> </html>