Javascript 使用 onchange 更改变量值
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/7538136/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
提示：将鼠标放在中文语句上可以显示对应的英文。显示中英文
时间：2020-08-24 02:38:36 来源:igfitidea点击:
Change variable value using onchange
提问by no_freedom
I want to change the value of valueusing a changeevent listener. Is it possible? Here is my sample code:
我想更改value使用change事件侦听器的值。是否可以？这是我的示例代码：
<select name="select1" onchange="updatevariable(this.value)">
<option value="2" >2</option>
<option value="15" >15</option>
</select>
<script type="text/javascript">
value = "test";
function updatevariable(data) {
value = data;
}
alert(value); // It should be 2/15
</script>
回答by Marek Sebera
You have alert()in wrong place
你alert()在错误的地方
<select name="select1" onchange="updatevariable(this.value)">
<option value="2" >2</option>
<option value="15" >15</option>
</select>
<script type="text/javascript">
var value = "test";
function updatevariable(data) {
value = data;
alert(value);
}
</script>
In your code it is loaded right after the script is loaded,
you have to modify it to be called right after change
在您的代码中，它在脚本加载后立即加载，
您必须修改它才能在更改后立即调用
