Apply的应用

 1 # 应用于替换对象
 2 function People(name, age){
 3     this.name = name;
 4     this.age = age; 
 5 }
 6 
 7 function Worker(name, age, job){
 8     People.apply(this, arguments);
 9     this.job = job
10 }
11 
12 var worker = new Worker(‘小明‘, 23, ‘coder‘);
13 
14 worker.name #=> ‘小明‘;
15 worker.age #=> 23;
16 worker.job #=> ‘coder‘; 
17 
18 # 应用于平铺数组参数
19 
20 var a = [1,2,3],
21     b = [4,5];
22 
23 Array.prototype.push.apply(a, b); #=> a = [1, 2, 3, 4, 5]
24 
25 a.push(b); #=> a = [1, 2, 3, [4,5]]
26 
27 Math.math(null, [1,2,3,4,5]) #=> 5