The This scope in JavaScript

The This scope in JavaScript

The difference between this scope Java in JavaScript is that this in Java is determined in the compilation,

The This in JavaScript is determined at run time, with different invocation methods, which determines that this in JS points to a different object.

Code implementation:

　　 This scope
　　 functionSayname () {
　　　　 Console.LogThis.Name;
　　　　 Console.LogThis ===d1);
　　　　 Console.LogThis ===d2);
　　　　 Console.Logthis = = =Window;

}
Sayname ();

functionPerson (name, age) {
　　　　 This.Name = Name;
　　　　 This.Age = Age;
　　　　 This.Sayname =sayname

var D1 = new person ( "Ricky" ,24) ;
D1. sayname ()
var D2 = new person (" Rose ",24) D2. sayname () ;

Execution: Sayname (); When this sentence prints a value of true Console.log (this ===window);

Execution: D1.sayname (); When, this sentence prints a value of true Console.log (THIS===D1);

Execution: D2.sayname (); When this sentence prints a value of true Console.log (this ===d2);

 

This scope in JavaScript