javascript中call和apply的用法示例分析

/*
* 矩形
*/
function Rectangle(len,width) {
this.len = len;
this.width = width;
 
}
/*
* 乘以
*/
function multiply(a,b) {
return a * b;
}
// 矩形实例
var rectangle = new Rectangle(15, 30);
//求矩形面积
var proportion = multiply.call(rectangle,rectangle.len, rectangle.width);
// 等价于call
//var proportion = multiply.apply(rectangle,[rectangle.len, rectangle.width]);
 
document.write("矩形的面积是："+proportion);
document.write("<br/>");
 
document.write("/***********************分割线********************************/<br/>");
 
// 实现继承
function Persion(name) {
this.name = name;
this.sayHello = function () {
return "hello，"+this.name;
}
}
 
function Student(name,sex,school) {
Persion.call(this,name);
this.sex = sex;
this.school = school;
 
this.mySex = function () {
return this.sex;
}
this.mySchool = function () {
return this.school;
}
}
 
var stu = new Student('fengjx','男','广西机电职业技术学院')
 
document.write("stu sayHello："+stu.sayHello());
document.write("<br/>");
document.write("stu sex is："+stu.mySex());
document.write("<br/>");
document.write("stu school is ："+stu.mySchool());
document.write("<br/>");