look at the following code: function test(){ console.log(this === window); show(); window.show(); function show(){ console.log(this === window, fn ); } } function show(){ console.log(this === window, local ); } tes...
var a = 10; var obj1 = { a: 20, fn: (function() { this.a *= 2; a = 5; var a = 6; return function() { this.a *= a; console.log(a) } })() } var obj2 = { a: 30 } var fn = obj1.f...
< H1 > Code < H1 > undefined (node:5784) UnhandledPromiseRejectionWarning: TypeError: Cannot read property name of undefined at say (D: NodeJS Test test2.js:18:22) ...
in jQuery ajax, why does the this under the data attribute point to my vue instance? As follows: vue data(){ return{ name: test , age:18, } } ajax methods:{ getData(){ $.ajax({ url: test.php , type: post , ...
Why is the value of this tag 1 and this tag 2 different when the second callback is made by the two calls ? function a (val, callback) { callback.call(a,val,callback) } a(1,function b (val ,callback) { console.log(this, 1 ) ...
1, commonfun.js: export default { va:{ 000 : "0", 001 : "1", 002 : "2 }, func:(retcode)=>{ console.log(this); return this.va[retcode]; } } 2, main.js: import vue related dependencies im...
these two are learning the relevant syntax of ES6. When I learned about the this problem of the arrow function, when I compared it with the this in ES5, I found that the following line of code got incredible results: var age = 77; function foo() { ...
when I read the book introduction to ES6, I introduced the arrow function this . The immobilization of this is not because there is a mechanism for binding this inside the arrow function, but because the arrow function does not have its own this, at al...
JavaScript Advanced programming (3rd Edition) P144 the meaning expressed in (2). It s not what I understand. -reference elevation content start- English explanation To create a new instance of Person, use the new operator. Calling a constructor i...
Test and reflection triggered by the "Communication between non-parent and Child components " section of the official website tutorial: is about creating two child components, and the value of component an is passed to component b. <!DOCTYPE html&...
code <script> var num = 100; var obj = { num: 200, inner: { num: 300, print: function () { console.log(this.num); ...
problem description Nuxt.js framework to dock webscoket or timer polling, close the scoket connection or clear the timer before the page jumps the environmental background of the problems and what methods you have tried there are no beforeRouterL...
CREATE TABLE test1 ( id int (11) NOT NULL AUTO_INCREMENT, name varchar (20) DEFAULT NULL, code varchar (50) DEFAULT NULL, PRIMARY KEY ( id ), KEY idx_code ( code ) CREATE TABLE test2 ( id int (11) NOT NULL AUTO_INCREMENT, name varc...
the interface I developed in win7, other people s notebooks (such as window 10) is usually 125% or 150%, which causes an abnormal display when I open the browser. is there any way to deal with this problem? ...
dynamic links are https: www.domain.com index.php admin login pseudo-static is https: www.domain.com api admin login I haven t contacted Nginx,. How do you write this rule? ...
problem description Why is it that after manually loading ctx into the stack, current_app still does not point to app the environmental background of the problems and what methods you have tried related codes Please paste the code text below...