如何在旧数据之前而不是之后插入新数据

Question

I perform the php script to show random data. 我执行php脚本以显示随机数据。 I use ajax get to get data from the php script and continue getting data from the php script every 1 seconds. 我使用ajax get从php脚本获取数据，并继续每1秒从php脚本获取数据。 I also perform removal of the last row if the count is more or eqaul to 4. HOwever, my output is backward. 如果计数大于或等于4，我还将执行最后一行的删除。但是，我的输出是向后的。 I want to append new data before old data. 我想在旧数据之前附加新数据。

php script PHP脚本

<?php


$countryarr = array("UNITED STATES", "INDIA", "SINGAPORE","MALAYSIA","COLOMBIA","THAILAND","ALGERIA","ENGLAND","CANADA","CHINA", "SAUDI ARABIA");
$length = sizeof($countryarr)-1;
$random = rand(0,$length);
$random1 = rand(0,$length);

$random_srccountry = $countryarr[$random];
$random_dstcountry = $countryarr[$random1];
echo "<div>[X] NEW ATTACK: FROM [".$random_srccountry."] TO [".$random_dstcountry."]  </div>";
?>

html code HTML代码

<html>
<head>
<title>Add new data</title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<style>
#result {
    width: 500px;
    height:500px;
    border-style: solid;
    border-color: black;
}
</style>
</head>
<body>
<div id="result"></div>

<script>
var $auto_refresh = setInterval(function() {
    var $count = $('#result div').length;

    while ($count >= 4) {
    $('result div:last-child').remove();
    $count = $('#result div').length;
    }
    updateServer();
}, 1000);
//Remove last div if the count is more than 4
function updateServer() {
    $.get({
            url: 'randomData.php',
            dataType: 'text',
            success: randomdata
        });
}

function randomdata(val) {
        $('#result').append(val); //i want to insert before in other words new data appear at the top and old data remain down
}
</script>
</body>
</html>

I thought of using before or insertbefore to insert new data before the old data. 我想到了使用before或insertbefore在旧数据之前插入新数据。 I also used node to insert before.It does not work. 我也用过node来插入，这行不通。 Please help me. 请帮我。 thank you.. 谢谢..

Answer 1

You have to use prepend() from jquery : 您必须使用jquery的prepend（）：

function randomdata(val) {
    $('#result').prepend(val);
}

EDIT 编辑

I noticed an other error : $('result div:last-child').remove(); 我注意到另一个错误： $('result div:last-child').remove(); should be $('#result div:last-child').remove(); 应该是$('#result div:last-child').remove();

That's probably why it don't change, when it's at 4 divs it doesn't delete and redo the count, so you get stuck inside the while ... The fix from below should solve the problem 这可能就是为什么它不改变的原因，当它在4格时不会删除并重做计数，因此您陷入了困境……下面的修复应该可以解决问题

如何在旧数据之前而不是之后插入新数据

问题描述

1 个解决方案

解决方案1
0 已采纳 2017-10-06 14:34:58

如何在旧数据之前而不是之后插入新数据

问题描述

1 个解决方案

解决方案1 0 已采纳 2017-10-06 14:34:58

解决方案1
0 已采纳 2017-10-06 14:34:58