JS冒泡排序

<script>
var arr=new Array(34,23,56,78,12,5);
for(var i=0;i<arr.length;i++){
    for (var j = 0;j<arr.length-1;j++){
            var x  ;
        if( arr[j+1]<arr[j]){
            x = arr[j];
            arr[j] = arr[j+1];
            arr[j+1] = x;
        }
    }
}
for (var y in arr) {
    console.log(arr[y]);
}
</script>