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/>");