如果选中复选框，我该如何获取？ [英] How do I get if a checkbox is checked or not?
本文介绍了如果选中复选框，我该如何获取？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
由于某种原因，我的窗体不想得到复选框的值...我不知道它是否是我的编码，但是当我尝试和 alert（）的值，我得到 undefined 作为结果。我错了什么？
For some reason, my form does not want to get the value of a checkbox... I am not sure if it is my coding or not, but when I try and alert() the value, I get undefined as a result. What do I have wrong?
<head>
<script>
var lfckv = document.getElementById("lifecheck").checked
function exefunction(){
alert(lfckv);
}
</script>
</head>
<body>
<label><input id="lifecheck" type="checkbox" >Lives</label>
</body>
EDIT
我尝试将它改为
function exefunction() {
alert(document.getElementById("lifecheck").checked);
}
但现在它甚至不想要 execute 。出现了什么问题？
But now it doesn't even want to execute. What's going wrong?
推荐答案
将 var lfckv 当执行该行时，主体尚未解析，并且元素lifecheck不存在。这完全正常：
Place the var lfckv inside the function. When that line is executed, the body isn't parsed yet and the element "lifecheck" doesn't exist. This works perfectly fine:
<html>
<head>
<script language="javascript" type="text/javascript">
function exefunction(){
var lfckv = document.getElementById("lifecheck").checked;
alert(lfckv);
}
</script>
</head>
<body>
<label><input id="lifecheck" type="checkbox" >Lives</label>
<button onclick="exefunction()">Check value</button>
</body>
</html>
这篇关于如果选中复选框，我该如何获取？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
