九.筛选出数组中大于10的值

<script>
var arr1=[10,1,5,9,6,4,20,30,28];
var arr2=[];
var j=0;
for(var i=0;i<arr1.length;i++){
  if(arr1[i]>10){
    arr2[j]=arr1[i];   //删除var j=0;将arr2[j]=arr1[i]换成arr2[arr2.length]=arr1[i]效果一样
    j++;
  } 
}
console.log(arr2)
</script>