Javascript 如何在第二次选择中自动选择与第一次选择相同的数值选项?
新的引导和JavaScriptJavascript 如何在第二次选择中自动选择与第一次选择相同的数值选项?,javascript,php,twitter-bootstrap,select,Javascript,Php,Twitter Bootstrap,Select,新的引导和JavaScript <select id="list1" name="list1" class="form-control" required/> <?php for ($h = 1; $h <= 7; $h++) echo "<option value='$h'>$h</option>"; ?> </select> <select id="list2" name="list2" class="form-co
<select id="list1" name="list1" class="form-control" required/>
<?php
for ($h = 1; $h <= 7; $h++) echo "<option value='$h'>$h</option>";
?>
</select>
<select id="list2" name="list2" class="form-control" required/>
<?php
for ($h = 1; $h <= 7; $h++) echo "<option value='$h'>$h</option>";
?>
</select>
您可以使用HTMLSelectElement
的属性:
const firstList=document.getElementById('list1');
const secondList=document.getElementById('list2');
firstList.addEventListener('change',()=>{
secondList.selectedIndex=firstList.selectedIndex;
});代码>
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您可以使用HTMLSelectElement
的属性:
const firstList=document.getElementById('list1');
const secondList=document.getElementById('list2');
firstList.addEventListener('change',()=>{
secondList.selectedIndex=firstList.selectedIndex;
});代码>
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