[JS] the problem pointed by this

Every time the parser calls the function, it passes an implicit parameter to the function , The implicit parameter is this,this It points to an object , This object we call function execution Context object , Depending on how the function is called ,this Will point to different objects .

1. Call... As a function ,this It's always window

function fun(){
    
    console.log(this)
}
//  Call... As a function ,this yes window
fun();

2. When called as a method ,this Is the object of the called method

function fun(){
    
    console.log(this)
    console.log(this.name)
}
var name = " Overall name attribute "
var obj = {
    
    name:" La la la ",
    sayName:fun,
}
var obj2 = {
    
    name:" Lulu, Lulu ",
    sayName:fun,
}

//  Call... As a method ,this yes obj
obj.sayName();
obj.sayName();
fun();

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