（1）深度复制方法

function find(arr,func){
    return arr.filter(func)[0];    
}
export default function deepCopy(obj,cache=[]){
    if(obj === null || typeof obj !== "object"){
        return obj;
    }
    const had = find(cache,c => c.orignal === obj);
    if(had){
        return had.copy;
    }
    const copy = Array.isArray(obj)?[]:{};
    cache.push({
        orignal:obj,
        copy
    });
    Object.keys(obj).forEach(key=>{
        copy[key] = deepCopy(obj[key],cache); 
    });
    return copy;
}

（2）数组去重较好的方法

Array.prototype.uniqued = function(){
this.sort();
var _arr = [this[0]];
for(var i = 1;i<this.length;i++){
    if(this[i] !== _arr[_arr.length - 1]){
    	_arr.push(this[i]);
    }
}
return _arr;
}

（3）识别是否是对象

alert(Object.prototype.toString.call(a) === ‘[object String]’) -------> true;
alert(Object.prototype.toString.call(b) === ‘[object Number]’) -------> true;
alert(Object.prototype.toString.call(c) === ‘[object Array]’) -------> true;
alert(Object.prototype.toString.call(d) === ‘[object Date]’) -------> true;
alert(Object.prototype.toString.call(e) === ‘[object Function]’) -------> true;
alert(Object.prototype.toString.call(f) === ‘[object Function]’) -------> true;

（4）快速排序
 方法一：
 function quickSort(arr){
	if(arr.length<=1){
		return arr;
	}    
	var middleIndex = Math.floor(arr.length/2);
	var mildleValue = arr.splice(middleIndex,1)[0];
	var left = [];
	var right = [];
	for(var i = 0;i < arr.length;i++){
		if(arr[i] < middleValue){
			left.push(arr[i]);
		}else{
			right.push(arr[i]);
		}
	}
	return quickSort(left).concat([middleValue],quickSort(right));
 }
 方法二：
 function quickSort(arr,left,right){
	if(Object.prototype.toString.call(arr) === "[object Array]" && typeof left === "number" && typeof right === "number"){
		if(left<right){
			var rightVal = arr[right],i = left - 1,temp;
			for(var j = 0;j <= right;j++){
				if(arr[j] < rightVal){
					i++;
					temp = arr[i];
					arr[i] = arr[j];
					arr[j] = temp;
				}	
			}
			quickSort(arr,left,i-1);
			quickSort(arr,i+1,right);
		}
		return arr;
	}else{
		return "参数不对！"
	}
 }