Javascript面向对象的几种写法

/*

* 1.

*/

function Balance(consume) {

    this.consume = consume

}

Balance.cash = 10000

Balance.prototype.count = function() {

    return Balance.cash – this.consume

}

var b = new Balance(2390)

console.log(‘余额为： $’ + b.count())

/*

* 2.

*/

var Balance = new Object()

Balance.cash = 10000

Balance.count = function(consume) {

    return ‘余额为： $’ + (this.cash – consume)

}

console.log(Balance.count(100))

/*

* 3.

*/

var Balance = function() {

    var blc = new Object()

    blc.cash = 10000

    blc.count = function(consume) {

        return ‘余额为： $’ + (this.cash – consume)

    }

    return blc

}

var b = new Balance()

console.log(b.count(9999))

/*

* 4.

*/

var Balance = new Function(

    “this.cash = 10000; this.count = function(consume){ return ‘余额为： $’+(this.cash – consume); }”,

)

console.log(new Balance().count(2000))

/*

* 5.（最常用）

*/

var Balance = {

    cash: 10000,

    count: function(consume) {

        return ‘余额为： $’ + (this.cash – consume)

    },

}

console.log(Balance.count(3750))