在下拉列表上使用jQuery val() [英] Using Jquery val() on a dropdown list

问题描述

除其他外，我试图提醒金额"下拉框中的所选值，该框中是1到10的数字列表.将生成该列表，然后将其插入到div中.

Among other things I am trying to alert the selected value in the 'Amount' drop down box which is a list of numbers from 1 to 10. The list is generated and then inserted in to a div.

// generate the amount dropdown list
var dropdown = "<select name=\"amount\">";
for(var i=1; i <= MAX_PRINT; i++) {
    dropdown = dropdown + "<option>" + i + "</option>"
}
dropdown = dropdown + "</select>";

jQuery("#" + divId).html("<div>Amount: " + dropdown + "</div></div>");


var amount = 1;

jQuery(document).ready(function() {
    amount = jQuery("#amount").val();
    alert(amount);
});

我的问题是:当我提醒金额时，为什么会产生未定义"?我希望它返回所选的数字

My question is: Why does it produce 'undefined' when I alert the amount? I am expecting it to return the selected number

推荐答案

请确保为您的选择提供一个ID，现在它只有一个名称.结果，您的jQuery('#amount')选择器未返回任何内容，这就是显示警报的原因 undefined.

Make sure you give your select an id—right now it just has a name. As a result, your jQuery('#amount') selector is not returning anything, which is why the alert is showing undefined.

var dropdown = "<select id='amount' name='amount'>";

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