The problem of this in javascript

 function People(name) {
            this.name = name;
            this.sayName = function () {
                console.log("my name is:" + this.name);
            }
        }
        People.prototype.walk = function () {
            console.log(this.name + " is walking"); this
        }
        var p1 = new People("");
        var p2 = new People("");

People.prototype.walk () Sorry, the problem is not fully described, so what does the this in this function represent

Javascript
Mar.10,2021
The direction of

this can only be determined when it is called, so you cannot determine the place where you add comments, or it conforms to those pointing methods. You can refer to how to call walk,. You can search for the relationship between this calling method and this pointing. You can search for this pointing .

print it out 

People.prototype.walk = function ()
{
    console.log(this);
}

https://www.cnblogs.com/pssp/., you can take a look at 

function People(name) {
    this.name = name;
    this.sayName = function () {
        console.log('my name is:' + this.name);
    }
}
People.prototype.walk = function () {
    console.log(this.name + ' is walking'); 
}
var p1 = new People('');
p1.sayName()
p1.walk();

/ / my name is: We
/ / We is walking

1. Ordinary function this pointing to problem: sayName () can be understood as closure, internal function can access external variables, this pointing to external name
2,: walk () function pointing to problem based on prototype chain this is based on inheritance of people prototype chain line. Walk () inherits all the attributes of the parent class, so the this here still points to the name
3 of the parent class. The pointing problem based on the arrow function this: this points to the upper level of the arrow function
Summary: the pointing of this is very complex, and the specific directivity problem should be considered according to the method in which the function is called. You do not know the javascript has a specific understanding of the direction and scope of this, I hope it will be helpful to you

Previous: What is the compatibility of mobile vw and vh adaptation scheme?

Next: Why does ESlint airbnb not recommend changing setState? in the componentDidMount lifecycle function of react

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b3eb4a-2c440.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b3eb4a-2c440.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?