用 jQuery 检查复选框是否被选中

Question

How can I check if a checkbox in a checkbox array is checked using the id of the checkbox array?

I am using the following code, but it always returns the count of checked checkboxes regardless of id.

function isCheckedById(id) {
  alert(id);
  var checked = $("input[@id=" + id + "]:checked").length;
  alert(checked);

  if (checked == 0) {
    return false;
  } else {
    return true;
  }
}

转载于:https://stackoverflow.com/questions/2204250/check-if-checkbox-is-checked-with-jquery

Answer 1

IDs must be unique in your document, meaning that you shouldn't do this:

<input type="checkbox" name="chk[]" id="chk[]" value="Apples" />
<input type="checkbox" name="chk[]" id="chk[]" value="Bananas" />

Instead, drop the ID, and then select them by name, or by a containing element:

<fieldset id="checkArray">
    <input type="checkbox" name="chk[]" value="Apples" />

    <input type="checkbox" name="chk[]" value="Bananas" />
</fieldset>

And now the jQuery:

var atLeastOneIsChecked = $('#checkArray:checkbox:checked').length > 0;
//there should be no space between identifier and selector

// or, without the container:

var atLeastOneIsChecked = $('input[name="chk[]"]:checked').length > 0;