Rails ERB select_标记，使用javascript更新默认值

我当前有一个select_标记，用于选择当前日期，如下所示（最后一个值指定选择哪一个）：

但是select_标记的ID标记是动态生成的，所以我不知道如何插入它

---

任何帮助都将不胜感激

您可以传入一个静态ID:

<%= select_tag(:day, options_for_select([['Sunday', 0], ['Monday', 1],
['Tuesday', 2], ['Wednesday', 3], ['Thursday', 4], ['Friday', 5],
['Saturday', 6]], Time.now.wday), id: 'static-id-of-select-tag') %>

如果您想要，甚至可以选择一个类：

<%= select_tag(:day, options_for_select([['Sunday', 0], ['Monday', 1],
['Tuesday', 2], ['Wednesday', 3], ['Thursday', 4], ['Friday', 5],
['Saturday', 6]], Time.now.wday), class: 'static-class-for-js') %>

---

最终解决方案，感谢Babar

<%= select_tag(:day, options_for_select([['Sunday', 0], ['Monday', 1], ['Tuesday', 2], ['Wednesday', 3], ['Thursday', 4], ['Friday', 5], ['Saturday', 6]], 0), id: 'static-id-of-select-tag') %>

<script>
function myFunction() {
var d = new Date();
var n = ndgetDay();

document.getElementById("static-id-of-select-tag").selectedIndex = n;
}
myFunction()
</script>

函数myFunction（）{
var d=新日期（）；
var n=ndgetDay（）；
document.getElementById（“选择标记的静态id”）。selectedIndex=n；
}
myFunction（）

语法错误，意外“，”，应为“）”…aturday'，6]]，Time.now.wday），id:“select标记的静态id…”^更正。我错过了包装支架！

<%= select_tag(:day, options_for_select([['Sunday', 0], ['Monday', 1],
['Tuesday', 2], ['Wednesday', 3], ['Thursday', 4], ['Friday', 5],
['Saturday', 6]], Time.now.wday), id: 'static-id-of-select-tag') %>

<%= select_tag(:day, options_for_select([['Sunday', 0], ['Monday', 1],
['Tuesday', 2], ['Wednesday', 3], ['Thursday', 4], ['Friday', 5],
['Saturday', 6]], Time.now.wday), class: 'static-class-for-js') %>

<%= select_tag(:day, options_for_select([['Sunday', 0], ['Monday', 1], ['Tuesday', 2], ['Wednesday', 3], ['Thursday', 4], ['Friday', 5], ['Saturday', 6]], 0), id: 'static-id-of-select-tag') %>

<script>
function myFunction() {
var d = new Date();
var n = ndgetDay();

document.getElementById("static-id-of-select-tag").selectedIndex = n;
}
myFunction()
</script>