javascript 从选择标签中获取选定的值
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Get selected value from select tag
提问by Caio Bianchi
When I select a value from the option and click on a button, I want to fetch the selected value with javascript. What am I doing wrong? My value is always 1.
当我从选项中选择一个值并单击一个按钮时，我想用 javascript 获取选定的值。我究竟做错了什么？我的值总是 1。
<select id="aand_select">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
// javascript code
// javascript代码
var e = document.getElementById("aand_select");
var quantity= e.options[e.selectedIndex].value;
回答by Caio Bianchi
This apparently will do
这显然会做
var e = document.getElementById("aand_select");
e.addEventListener('change', function(){
var quantity= e.options[e.selectedIndex].value;
console.log(quantity);
},false);??????????
回答by Dan Armstrong
Make sure that you are calling the javascript at the appropriate time. For example if you are calling it only when the page loads, the value will never change. Make sure you are calling it from an onClick() or some other event.
确保您在适当的时间调用 javascript。例如，如果您仅在页面加载时调用它，该值将永远不会改变。确保您是从 onClick() 或其他事件调用它。
