當用戶選擇下拉菜單時,如果所選下拉列表中的值不爲空,則該複選框將自動檢查。但是我遇到了「sel [i]是未定義的」錯誤。如果所選下拉列表的值不爲空,請選擇下拉菜單並自動選中複選框
JavaScript部分:
var chk = document.getElementsByTagName("input");
var sel = document.getElementsByTagName("select");
for (var i=0; i< sel.length; i++) {
sel[i].onchange = function(){
if (sel[i].value !== ''){
chk[i].checked = true;
}
else{
chk[i].checked = false;
}
};
}
HTML部分:
<form name="form1">
<div class="container">
<input id='checkbox_id1' name='checkbox_id1' type='checkbox' value='1' /></label>
Select
<label>
<select id="select_id1" name="select">
<option value=""></option>
<option value="111">111</option>
<option value="222">222</option>
</select>
</label>
<hr>
<input id='checkbox_id2' name='checkbox_id1' type='checkbox' value='1' /></label>
Select
<label>
<select id="select_id2" name="select">
<option value=""></option>
<option value="111">111</option>
<option value="222">222</option>
</select>
</label>
</div>
的jsfiddle:http://jsfiddle.net/planetoid/GwEuu/