Object Creation

[littlee]

/*
    工厂模式
    没有解决对象识别问题
*/
function createPerson(name, age, job) {
    var o = {};
    o.name = name;
    o.age = age;
    o.job = job;
    o.sayName = function() {
        console.log(this.name);
    };
    return o;
}

var p1 = createPerson('Lee', 22, 'Web Dev.');

/*
    构造函数模式
    每个方法都要在每个实例上重新创建一次
*/
function Person(name, age, job) {
    this.name = name;
    this.age = age;
    this.job = job;
    this.sayName = function() {
        console.log(this.name);
    };
}

var p1 = new Person('Lee', 22, 'Web Dev.');

/*
    原型模式
    原型上的属性是所有实例共享的，如果有引用类型会出问题（数组的操作）
    不能向构造器传递初始化参数
*/
function Person() {}
Person.prototype.name = 'Lee';
Person.prototype.age = 22;
Person.prototype.job = 'Web Dev.';
Person.prototype.sayName = function() {
    console.log(this.name);
};

var p1 = new Person();

/*
    构造器/原型组合模式
*/
function Person(name, age, job) {
    this.name = name;
    this.age = age;
    this.job = job;
    this.friends = ['you', 'me'];
}
Person.prototype = {
    constructor: Person,
    sayName: function() {
        console.log(this.name);
    }
};

/*
    动态原型模式
*/
function Person(name, age, job) {
    this.name = name;
    this.age = age;
    this.job = job;

    if (typeof this.sayName !== 'function') {
        Person.prototype.sayName = function() {
            console.log(this.name);
        };
    }
}

/*
    寄生构造器模式
    可以用于创建一个特殊的对象
*/
function Person(name, age, job) {
    var o = {};
    o.name = name;
    o.age = age;
    o.job = job;
    o.sayName = function() {
        console.log(this.name);
    };
    return o;
}

function SpecialArray() {
    var values = [];
    values.push.apply(values, arguments);
    values.toPipedString = function() {
        return this.join('|');
    };

    return values;
}
var colors = new SpecialArray('red', 'green', 'blue');
console.log(colors.toPipedString());

/*
    持久构造器模式
    不使用 new 进行调用
*/
function Person(name, age, job) {
    //create the object to return
    var o = {};
    //optional: define private variables/functions here
    //attach methods
    o.sayName = function() {
        console.log(name);
    };
    //return the object
    return o;
}