如何创建JS类/对象的多个实例？

Question

I would like to create multiple instances for apple in below code. how to achieve it. I don't want to change my object defining style.

var apple = {
    type: "macintosh",
    color: "red",
    getInfo: function () {
        return this.color + ' ' + this.type + ' apple';
    }
}

Thanks In Advance.

Answer 1

I suggest a constructor function for creating instances:

function apple(type, color){
    this.type = type;
    this.color = color;
}

apple.prototype.getInfo = function(){
    return this.color + ' ' + this.type + ' apple';
};

var apple1 = new apple('mac', 'red');
apple1.getInfo();

http://jsfiddle.net/6S5b5/

Answer 2

You can use this

function giveMeApple() {
    var apple = {
    type: "macintosh",
    color: "red",
    getInfo: function () {
        return this.color + ' ' + this.type + ' apple';
      }
    }

    return apple;
}

var apple1 = giveMeApple();
var apple2 = giveMeApple();

// Do something with apples 

Answer 3

You can use Object.create :

The Object.create() method creates a new object with the specified prototype object and properties.

var apple = {
    type: "macintosh",
    color: "red",
    getInfo: function () {
        return this.color + ' ' + this.type + ' apple';
    }
}

var otherApple = Object.create(apple);

If you need to support < IE 9, the above link contains a polyfill.

Answer 4

Usually, this would be a case where constructor functions come in handy. Johan's answer contains those. But since you don't want to change your object: Here you have another answer.

In addition to the answer of blunderboy you can also clone the object. There is no native function to do so, but it is easy to write one yourself.

function cloneObject(obj) {
    var obj2 = {},
        i;

    // Take every property of obj
    for (i in obj) {
        if (obj.hasOwnProperty(i)) {

            // And give obj2 the same property with the same value
            obj2[i] = obj[i];
        }
    }
}

apple2 = cloneObject(apple);

Answer 5

var Apple = function () {

            var AppleType = null;
            var AppleColor = null;
            var self = this;

            var OutPutAppleInfo = function () {
                var String = 'My Apple is ' + AppleType + ' And It Is ' + AppleColor + ' In Color.';
                console.log(String);
            }

            return {

                SetAppleColor: function (obj) {
                    AppleColor = obj;
                },
                SetAppleType: function (obj) {
                    AppleType = obj;
                },
                PrintAppleInfo: function () {
                    OutPutAppleInfo();
                }
            };
        }


        function Init()
        {
            var Apple1 = new Apple();
            var Apple2 = new Apple();
            var Apple3 = new Apple();

            Apple1.SetAppleColor('Yellow');
            Apple2.SetAppleColor('Green');
            Apple3.SetAppleColor('Red');

            Apple1.SetAppleType('macintosh');
            Apple2.SetAppleType('Food');
            Apple3.SetAppleType('Model');

            console.log('Apple1');
            Apple1.PrintAppleInfo();
            console.log('Apple2');
            Apple2.PrintAppleInfo();
            console.log('Apple3');
            Apple3.PrintAppleInfo();

        }