javascript面向对象实例

非私有属性

function Student(name, gender, age, grade, teacher){

this.name = name;

this.gender = gender;

this.age = age;

this.grade = grade;

this.teacher = teacher;

}

var bob = new Student("bob", "male", 15, 10, "Marlow");

alert(bob.age); //输出15

var susan = new Student("susan", "female", 10, 5, "Gresham");

alert(susan.gender); //输出 'female'

var bob = new Student("bob", "male", 15, 10, "Marlow");

alert(bob.age); //输出15     bob.age = 9;

alert(bob.age); //输出9;

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私有属性

function Student(name, gender, age, grade, teacher)     {

var studentName = name;

var studentGender = gender;

var studentGrade = grade;

var studentTeacher = teacher;

var studentAge = age;

this.getAge = function() {

return studentAge;

};

this.setAge = function(val){

studentAge = Math.abs(val); //使用绝对值，确保年龄是正值

};

}

var bob = new Student("bob", "male", 15, 10, "Marlow");

alert(bob.studentAge); //未定义，因为年龄在类定义中受私有保护

alert(bob.getAge()); //输出15     bob.setAge(-20);     alert(bob.getAge()); //输出20

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动态创建的访问器方法

function Student( properties ){

var $this = this;  //将类范围存储到名为$this的变量中

//迭代处理对象的属性

for ( var i in properties ) {

(function(i) {

// 动态创建访问器方法

$this[ "get" + i ] = function(){

return properties[i];

};

})(i);

}

}

// 创建一个新的用户对象实例，并传递属性的对象

var student = new Student({Name: "Bob",Age: 15,Gender: "male"});

alert(student.name); //因属性是私有的而未定义

alert(student.getName()); //输出 "Bob"

alert(student.getAge()); //输出15

alert(student.getGender()); //输出 "male"

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类的继承

function Worker() {

this.getMethods = function(properties, scope)

{         var $this = scope;  //将类范围存储到名为$this的变量中

//迭代处理对象的属性

for ( var i in properties ){

(function(i){                 // 动态创建访问器方法

$this[ "get" + i ] = function()

{

return properties[i];

};             //动态地创建一个分析整数，并确保是正值的更改器方法。

$this[ "set" + i ] = function(val) {

if(isNaN(val)) {

properties[i] = val;

}else{

properties[i] = Math.abs(val);

}

};

})(i);

}

};

}

// CommissionWorker "子类"和WageWorker "子类"

//继承Worker的属性和方法。

CommissionWorker.prototype = new Worker();

WageWorker.prototype = new Worker();

function CommissionWorker(properties) {

this.getMethods(properties, this);

//计算收入

this.getIncome = function(){

return properties.Sales * properties.Commission;

}

}

//要求有下列属性：薪水、每周小时数、每年周数

function WageWorker(properties) {

this.getMethods(properties, this);

//计算收入

this.getIncome = function() {

return properties.Wage * properties.HoursPerWeek * properties.WeeksPerYear;

}

}

var worker = new WageWorker(Name: "Bob", Wage: 10, HoursPerWeek: 40,WeeksPerYear: 48 });

alert(worker.wage); //未定义。薪水是私有属性。

worker.setWage(20); alert(worker.getName());   //输出 "Bob"

alert(worker.getIncome()); //输出 38,400 (20*40*48)

var worker2 = new CommissionWorker( {     Name: "Sue",     Commission: .2,     Sales: 40000 });

alert(worker2.getName());   //输出 "Sue"

alert(worker2.getIncome()); //输出8000（2% 乘40,000）