使用Javascript来选择多个选项 [英] Javascript to Select Multiple options

问题描述

我有一个允许多个选项的选择框。用户保存这些选项后，将它们存储在数据库表中。

然后我可以读取这个数据库表以获得他们再次选择的选项。我需要能够从数据库中获取这些数据，并将其放入一个数组中，然后让这些选择框中的选项在他们选择编辑选项时被预选。

将数据读入数组很好，我知道如何在选择框中选择一个选项，但是我不确定如何处理在javascript中选择的多个选项。

有人可以帮我弄清楚这样做所需的JavaScript吗？

解决方案

纯JavaScript解决方案

 < select id =choicemultiple =multiple> 
< option value =1>一个< / option> 
< option value =2> two< / option> 
< option value =3> three< / option> 
< / select> 
< script type =text / javascript> 
 
 var optionsToSelect = ['One'，'three']; 
 var select = document.getElementById（'choice'）; 
 
 for（var i = 0，l = select.options.length，o; i< l; i ++）
 {
 o = select.options [i]; 
 if（optionsToSelect.indexOf（o.text）！= -1）
 {
 o.selected = true; 
} 
} 
 
< / script> 
  

虽然我同意这应该在服务器端完成。

I have a form with a select box that allows multiple options. After a user saves these options, it stores them in a database table.

I can then read this database table to get the options they chose one again. I need to be able to grab this data from the database, put it into an array, then have the options in that select box to be pre-selected when they go to "Edit" their options.

Reading the data into an array is fine, and I know how to make a single option selected within a select box, however I'm not sure how to handle multiple options being selected in javascript.

Can someone help me figure out the javascript required to do this?

解决方案

A pure javascript solution

<select id="choice" multiple="multiple">
  <option value="1">One</option>
  <option value="2">two</option>
  <option value="3">three</option>
</select>
<script type="text/javascript">

var optionsToSelect = ['One', 'three'];
var select = document.getElementById( 'choice' );

for ( var i = 0, l = select.options.length, o; i < l; i++ )
{
  o = select.options[i];
  if ( optionsToSelect.indexOf( o.text ) != -1 )
  {
    o.selected = true;
  }
}

</script>

Although I agree this should be done server-side.

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