javascript - 如何在选项标签中显示 JavaScript 变量

Question

我需要在选项 block 中显示在 javascript 脚本中声明的变量。还会有一到两个选择 block ，具体取决于在此 block 中选择的选项。

    <select name="expiration_year" id="expiration_year" onchange="populate(this.id,'expiration_month','expiration_day')">

    <script>
    //variable declaration in JavaScript
    var year =  new Date().getFullYear();
    </script>

    //I want to display the variable stored in "year" where it is marked in the 
    //following code
    //this <option value=year> is using the variable correctly, the second 
    //half of the line isnt using the variable (which should have a value 
    //equaling the current year)
    //instead it simply says year
    <select>
    <option value=year>year</option>
    <option value=year+1>year+1</option>

    </select>        

Image of what current code produces when run

任何帮助都将不胜感激，我对网页编码和使用 java 脚本非常陌生。如果这个问题已经被提出并得到回答，我很抱歉。

Answer 1

您可以动态添加选项。

例如

// This assumes that this is the only select element on the page.
// Also, this would have to run in a script block 
// after the select element is added to the page.
var select = document.querySelector('select');
select.options.add(new Option(year));
select.options.add(new Option(year + 1));

// etc.