JavaScript에서 상속되지 않은 두 가지 메서드의 사용 예에 ​​대한 자세한 설명

window.firstName = "diz"; 
window.lastName = "song"; 
var myObject = { firstName: "my", lastName: "Object" }; 
function HelloName() { 
　　console.log("Hello " + this.firstName + " " + this.lastName, " glad to meet you!"); 
} 
HelloName.call(window); //huo .call(this); 
HelloName.call(myObject);

Hello diz song glad to meet you! 
Hello my Object glad to meet you!

function sum(num1, num2) { 
return num1 + num2; 
} 
console.log(sum.call(window, 10, 10)); //20 
console.log(sum.apply(window,[10,20])); //30

window.firstName = "diz"; 
window.lastName = "song"; 
var myObject = { firstName: "my", lastName: "Object" }; 
function HelloName() { 
console.log("Hello " + this.firstName + " " + this.lastName, " glad to meet you!"); 
} 
HelloName(); //Hello diz song glad to meet you! 
myObject.HelloName = HelloName; 
myObject.HelloName(); //Hello my Object glad to meet you!

function temp1() { 
console.log(this); //Object {} 
function temp2() { 
console.log(this); //Window 
} 
temp2(); 
} 
var Obj = {}; 
temp1.call(Obj); //运行结果见上面的注释！！！！

function temp1() { 
console.log(this); 
temp2(); 
} 
function temp2() { 
console.log(this); 
} 
var Obj = {}; 
temp1.call(Obj);