1、冒充方式-------实现继承
<script type="text/javascript">
function CreatPerson (name,age) {
this.name = name;
this.age = age;
this.sayHi = function () {
alert("哈哈");
}
}
function CreatStudent (name, age, banJi) {
// 通过冒充实现子类继承父类的方法、属性
this.newFn = CreatPerson;
//1、 给this（也就是学生对象）添加一个新的方法，也就是CreatPerson这个构造函数
this.newFn(name, age);
//2、 执行新添加进去的函数，通过this.newFn调用父类函数,进而修改了父类函数中this指针的指向，
delete this.newFn; // 3、删除这个函数（过河拆桥）
this.banJi = banJi;
this.study = function () {
alert("学习");
};
}
var stu1 = new CreatStudent("李威", 23, 9);
console.log(stu1.study);
</script>
复制代码
2、原型方式实现继承
<script type="text/javascript">
function CreatAnimal (name, age) {
this.name = name;
this.age = age;
this.sayHi = function () {
alert("你好");
};
}
CreatAnimal.prototype.gender = "男";
CreatAnimal.prototype.sayBye = function () {
alert("走吧");
}
function CreatDog (name, age, leg) {
this.leg = leg;
this.lookDoor = function () {
alert("看门");
}
}
把父类的对象当做子类的原型，这样就把子类的原型和父类的原型联系在一起了
CreatDog.prototype = new CreatAnimal("李淑芬",12);
因为对象的constructor属性值是取决于原型中的constructor值的，而此时原型中constructor值指向的是父类函数，所以要修改原型的constructor值为子类函数，保证继承关系不混乱
CreatDog.prototype.constructor = CreatDog;
var dog = new CreatDog("旺财", 12, 4);
// console.log(dog.name);
console.log(dog.gender);
dog.sayBye();
console.log(dog.constructor == CreatDog);
// dog.sayHi();
</script>
3、call方式实现继承
<script type="text/javascript">
//父类构造函数
function CreatPerson(name,age,gender){
this.name = name;
this.age = age;
this.gender = gender;
this.walk = function(){
console.log("走的舒服吗")
}
//父类原型
/*CreatPerson.prototype.walk = function(){
console.log("走的舒服吗")*/
}
//子类
function CreatStudent(name,age,gender,hobby){
CreatPerson.call(this,name,age,gender)
this.hobby = hobby;
/*this.walk =function(){
console.log("走的爽不")
};*/
this.study = function(){
console.log("学的爽不")
}
}
//子类原型方法
/*CreatStudent.prototype.walk = function(){
console.log("走的很不爽")
}
CreatStudent.prototype.study = function(){
console.log("学习好舒服")
}*/
//创建子对象
var s1 = new CreatStudent("李培舟",23,"男","吃")
console.log(s1.name);
console.log(s1.age);
console.log(s1.gender);
console.log(s1.walk());
console.log(s1.study());
</script>
4、组合方式实现继承
<script type="text/javascript">
//父类构造函数
function CreatPerson(name,age,gender){
this.name = name;
this.age = age;
this.gender = gender;
/*this.walk = function(){
console.log("走的舒服吗")*/
}
//父类原型
CreatPerson.prototype.walk = function(){
console.log("走的舒服吗")
}
//子类
function CreatStudent(name,age,gender,hobby){
CreatPerson.call(this,name,age,gender)
this.hobby = hobby;
/*this.walk =function(){
console.log("走的爽不")
};*/
/*this.study = function(){
console.log("学的爽不")
}*/
}
//子类原型方法
/*CreatStudent.prototype.walk = function(){
console.log("走的很不爽")
}*/
CreatStudent.prototype.study = function(){
console.log("学习好舒服")
}
CreatStudent.prototype = new CreatPerson();
CreatStudent.prototype.constructor = CreatPerson;
//创建子对象
var s1 = new CreatStudent("李培舟",23,"男","吃")
console.log(s1.name);
console.log(s1.age);
console.log(s1.gender);
console.log(s1.hobby);
console.log(s1.walk());
</script>
