HTMLFormElement.elements - Web APIs 编辑

The HTMLFormElement property elements returns an HTMLFormControlsCollection listing all the form controls contained in the <form> element. Independently, you can obtain just the number of form controls using the length property.

You can access a particular form control in the returned collection by using either an index or the element's name or id.

Prior to HTML 5, the returned object was an HTMLCollection, on which HTMLFormControlsCollection is based.

Note: Similarly, you can get a list of all of the forms contained within a given document using the document's forms property.

Syntax

nodeList = HTMLFormElement.elements

Value

An HTMLFormControlsCollection containing all non-image controls in the form. This is a live collection; if form controls are added to or removed from the form, this collection will update to reflect the change.

The form controls in the returned collection are in the same order in which they appear in the form by following a preorder, depth-first traversal of the tree. This is called tree order.

The elements included by HTMLFormElement.elements and HTMLFormElement.length are the following:

• <button>
• <fieldset>
• <input> (with the exception that any whose type is "image" are omitted for historical reasons)
• <object>
• <output>
• <select>
• <textarea>

No other elements are included in the list returned by elements, which makes it an excellent way to get at the elements most important when processing forms.

Example

Quick syntax example

In this example, we see how to obtain the list of form controls as well as how to access its members by index and by name or ID.

<form id="my-form">
  <input type="text" name="username">
  <input type="text" name="full-name">
  <input type="password" name="password">
</form>

var inputs = document.getElementById("my-form").elements;
var inputByIndex = inputs[0];
var inputByName = inputs["username"];

Accessing form controls

This example gets the form's element list, then iterates over the list, looking for <input> elements of type "text" so that some form of processing can be performed on them.

var inputs = document.getElementById("my-form").elements;

// Iterate over the form controls
for (i = 0; i < inputs.length; i++) {
  if (inputs[i].nodeName === "INPUT" && inputs[i].type === "text") {
    // Update text input
    inputs[i].value.toLocaleUpperCase();
  }
}

Disabling form controls

var inputs = document.getElementById("my-form").elements;

// Iterate over the form controls
for (i = 0; i < inputs.length; i++) {
  // Disable all form controls
  inputs[i].setAttribute("disabled", "");
}

Specifications

Browser compatibility

BCD tables only load in the browser