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How do I check whether a checkbox is checked in jQuery?

How do I check whether a checkbox is checked in jQuery?

Matthew C.

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The ProblemJump To Solution

You have a checkbox with an id property. How can you find out if it’s checked using jQuery?

The Solution

jQuery selectors allow you to find and select HTML elements by their attributes such as name, ID, class, or type. The selectors all start with a dollar sign and parentheses: $().

To check if a checkbox is checked, get the checkbox by its id using the jQuery selector. Then use the is() method:

Click to Copy
const isChecked = $("#" + id).is(":checked");

The is() method checks for a :checked CSS pseudo-class, which would be added to a checkbox if it’s checked. It returns true if the checkbox is checked.

You can do the same check using vanilla JavaScript:

Click to Copy
const isChecked = document.getElementById(id).checked;

The getElementById element selector is used to find an element by id. The boolean checked property exists on checkbox inputs.

To check if a checkbox is checked dynamically, you can use an id input and add a button to run a function to check if the checkbox is checked. For example, the following code example has two checkboxes, an id input, and a button to check if the input is checked:

Click to Copy
    <fieldset>
      <legend>Choose food your items</legend>

      <input type="checkbox" id="salad" name="salad" />
      <label for="salad">Salad</label>

      <input type="checkbox" id="chips" name="chips" />
      <label for="chips">Chips</label>
    </fieldset>

    <input id="checkboxIdInput" placeholder="Add checkbox id to check" />
    <button id="checkBtn">Check if checked</button>

The isCheckedJQuery function in the code below gets the element by id using the jQuery selector. If the element exists, is a checkbox, and is checked, then the function returns true, else it returns false.

Click to Copy
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.1/jquery.min.js"></script>

<script>
const checkboxIdInput = document.getElementById("checkboxIdInput");
const checkBtn = document.getElementById("checkBtn");

function isCheckedJQuery() {
  const el = $(`#${checkboxIdInput.value}`)[0];
  if (
    el
    && el.type === "checkbox"
    && $(`#${checkboxIdInput.value}`).is(":checked")
  ) {
    console.log("is checked");
    return true;
  }
  console.log("is not checked");
  return false;
}

checkBtn.addEventListener("click", isCheckedJQuery);
</script>

Using vanilla JavaScript, the check function would be slightly different:

Click to Copy
function isCheckedVanillaJS() {
  const el = document.getElementById(checkboxIdInput.value);
  if (el && el.type === "checkbox" && el.checked) {
    console.log("is checked");
    return true;
  }
  console.log("is not checked");
  return false;
}
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