function insertSort(arr){
var len = arr.length
for(var i=1;i<len;i++){
var temp = arr[i]
var j = i-1
while(arr[j]>temp){
arr[j+1]=arr[j]
j--
}
arr[j+1]=temp
}
return arr
}
var arr = [5,3,2,7,8]
console.log(insertSort(arr)) //[2,3,5,7,8]