<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<script>
function sum() {
// arguments; 类数组
/*console.log(arguments instanceof Array);// true
arguments.sort(function (a,b) {
return a-b;
})*/
//arguments.prototype = Array.prototype; 因为只有函数才具有prototype属性，所以，不能这种方式更改；
// 这种继承方式在IE10及以下是不兼容的；
arguments.__proto__=Array.prototype;
console.log(arguments);
arguments.sort(function (a,b) {
return a-b;
});
arguments.pop();
arguments.shift();
var t = 0;
for(var i=0;i<arguments.length;i++){
t+=arguments[i];
}
console.log(t / arguments.length);
}
//sum(97,96,100,90,92,85)
Array.prototype.myPop = function () {
var last = this[this.length-1]
this.length--;
return last;
}
var ary =[12,3,4,6];
ary.myPop();
console.log(ary);
// push shift unshift reverse indexOf slice splice
</script>
</body>
</html>
