js 定義函數的幾種方法 以及如何調用

/*1.方法調用模式：
    先定義一個對象，而後在對象的屬性中定義方法，經過myobject.property來執行方法，this即指當前的myobject 
    對象。*/
        var car = {
            carId:123,
            carName:"奧迪",
            carColor:"red",
            say:function(){
                console.log(this.carName+" color is "+this.carColor);
            }
        };
        car.say();

    /*2.函數調用模式
    定義一個函數，設置一個變量名保存函數，這時this指向到window對象。*/
        var mycar = function(name,color){
        　　return "my car is " +color+" and "+name ;
        }
        console.log(mycar("奧迪","紅色"));

    /*3.構造器調用模式
    定義一個函數對象，在對象中定義屬性，在其原型對象中定義方法。在使用prototype的方法時，必須實例化該對象才能調用其方法。*/
        var yourcar = function(name,color){
            this.name = name;
            this.color = color;
        };
        yourcar.prototype ={
            say:function(){
                console.log("your car is " +this.name + " and " +this.color);
            }
        };
        var yourcar = new yourcar("奔馳","藍色");
        yourcar.say();

    /*4.apply,call調用模式*/
        function count(num1, num2) { 
            return num1 + num2; 
        } 
        console.log(count.call(window, 10, 10)); //20 
        console.log(count.apply(window,[10,20])); //30

        window.a=100;
        window.b=300;
        var myobject={a:40,b:50};
        var sum = function(){
        　　return this.a+this.b;
        };
        var sum1 = sum.call(window); 
        // var sum2 = sum.call(myobject);
        var sum2 = sum.apply(myobject); 
        console.log(sum1+"========="+sum2);

        // 發現apply()和call()的真正用武之地是可以擴充函數賴以運行的做用域，若是咱們想用傳統的方法實現
        window.a=100;
        window.b=300;
        var myobject={a:40,b:50};
        function sum(){
            console.log(this.a+this.b);
        }
        console.log(sum());
        myobject.sumnumber = sum;
        console.log(myobject.sumnumber());

        window.color = "red"; 
        var o = { color: "blue" }; 
        function sayColor(){ 
            console.log(this.color); 
        } 
        sayColor();
        var OSayColor = sayColor.bind(o); 
        OSayColor(); //blue