topic description A method under the constructor (non-static method) does not want to execute the constructed method related codes Please paste the code text below (do not replace the code with pictures) class website extend site { ...
learn the constructor and encounter the following code when doing exercises the code is as follows function Fn(){ return this; } Fn.prototype.getNum = function(){ console.log(3); }; new new Fn().getNum (); Why is the output 3? what I under...
I have a base class, Base.php, that initializes the constructor. public function __construct() { parent::__construct(); $this->authWen(); } The constructor calls a permission verification method. However, in addition to true...
I encountered some confusion when learning the prototype chain as follows: in some blogs (such as Ruan Yifeng s blog), it is said: JavaScript natively provides Object objects, and all other objects inherit from Object objects, that is, those o...
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...
I javascript A novice, recently encountered a problem that I have been unable to understand, as follows: var A = function() { return new B() } var B = function() { this.name = B } var a = A() console.log(Object.getPrototypeOf(a) == B.pro...
CPP11 allows list initialization for all objects, and because the constructor body is assigned, references and const variables must be initialized first, so you must use list initialization, so how is it initialized before CPP11? ...
when referencing popper.js, if packaging does not rule out popper.js, calling new PopperJS, an error will be reported let PopperJS = require( . popper ); let popper = new PopperJS(); PopperJS is not a constructor webpack.base.conf.js: ...
I js novice, recently encountered a little question when learning the content of the object, as follows: personal understanding: every time an instance object is generated using the new command, all the properties in the constructor will be define...
has been prompting the path error, is it the baseUrl I misquoted, solve! html: <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Document< title> < head> <...
The code is basically typed according to the flask book whose cover is a dog . @users.before_app_request def before_request(): if current_user.is_authenticated: current_user.ping() if not current_user.confirmed an...
to make a recharge diamond system, I have no experience. I would like to ask the gods to make recharge records and expense records in one table, or separately from two tables? What are the advantages and disadvantages of each? ...
English without stutter or stutter is not obvious each stutter needs to kill the impression note process and then reopen it to be smooth for a while does anyone have a solution? The computer is equipped with a standard 15-inch computer for 17 years,...
just read the document ts when I saw that the tuple was out of bounds, I tried the following let x: [string, number]; x = [ hello , 10]; : x[3] = world ; OK, (string | number) console.log(x[5].toString()); OK, string number toStr...