基于原型扩展方法

数值去重

function unque(ary){
let obj = {};
for(var i = 0;i<ary.length-1;i++){
	   let item = ary[i];
	   if(typeof obj[item] !== 'undefined'){
	   		ary[i] = ary[ary.length-1];
	   		ary.length--;
	   		i--;
	   		continue;
	   }
	   obj[item] = item
}
obj = null;
return ary;
}
let ary = [12,123,12,13,5,2,123,123,5,12,16];

2.基于原型扩展

~function(){
	function myUnque(){
  let obj = {};
  for(var i = 0; i<this.length-1;i++){
      let item = this[i]
      if(typeof obj[item]!=="undefined"){
          this[i] = this[this.length-1]
          this.length--;
          i--;
          continue;
      }
      obj[item] = item
  }
  obj = null;
  return this;
	
	}
	Array.prototype.myUnque = myUnque

}()

let ary = [12,123,12,13,5,2,123,123,5,12,16];
ary.myUnque();