jQuery: find input field closest to button

问题

I have a large HTML form with multiple input fields (one in each row). Among these I have several fields with a specific class that appear left from a button. There are no other buttons or fields in these rows so they only contain the field and button as below.

How can I get the ID of such a field when clicking on the button right from it, i.e. closest to it ?

All fields in question look like this:

<input type="text" class="dateField" data-date-format="yyyy-mm-dd" id="field1" name="field1" />

All buttons in question look like this:

<button type="button">Select Date</button>

Thanks for any help with this, Tim.

回答1:

Because <input> is to the left of <button> you can find it like this:

$('button').on('click', function(){
    alert($(this).prev('input').attr('id'));
});

---

If <input> was after <button> then you can find it like this:

$('button').on('click', function(){
    alert($(this).next('input').attr('id'));
});

回答2:

You can go to parent of button using parent() and the find the input in descendants using find()

OR, if you have multi-level descendant

$(this).parent().find('.dateField')

OR, if you have single level descendants

$(this).parent().children('.dateField')

or

$(this).siblings('.dateField');

Similarly you can use next() or prev()

回答3:

Use .prev() or .next() if they're next to each other. (This should be fastest.) Otherwise you can also use .closest() to simply find closest instance of that class.

The documentation should be more than enough help.

Edit: You can also use .siblings() to search through siblings of that element.

来源：https://stackoverflow.com/questions/20357017/jquery-find-input-field-closest-to-button