js的排序算法

/*冒泡排序*/function bubbleSort(arr){
    var len = arr.length;    for(var i = 0;i<len-1;i++){        for(var j = i+1;j<len-i-1;j++){            if(arr[j]>arr[j+1]){                var temp = arr[j+1];
                arr[j+1] = arr[j];
                arr[j] = temp
            }
        }
    }    return arr
}

/*快速排序排序*/var quickSort = function(arr){
    if(arr.length<=0){        return arr;
    }    var midIndex = Math.foor(arr.length/2);    var midValue = arr.splice(midIndex,1);    var left =[];    var right = [];    for(var i =0;i<arr.length;i++){        if(arr[i]<midValue){
            left.push(arr[i]);
        }else{
            right.push(arr[i]);
        }
    }    return quickSort(left).concat(midValue,quickSort(right));
}

/*选择排序*/function selectionSort(arr){
    var len = arr.length;    var midIndex,temp;    for(var i =0 ;i<len-1;i++){
        midIndex = i;        for(var j=i+1;j<len;j++){            if(arr[j]<arr[midIndex]){
                midIndex = j;
            }
        }
        temp = arr[i];
        arr[i]= arr[midIndex];
        arr[midIndex] = temp;
    }    return arr
}