HTMLOutputElement

Baseline Widely available *

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨August 2016⁩.

* Some parts of this feature may have varying levels of support.

TheHTMLOutputElement interface provides properties and methods (beyond those inherited fromHTMLElement) for manipulating the layout and presentation of<output> elements.

Instance properties

This interface also inherits properties from its parent,HTMLElement.

HTMLOutputElement.defaultValue: A string representing the default value of the element, initially the empty string.
HTMLOutputElement.formRead only: AnHTMLFormElement indicating the form associated with the control, reflecting theform HTML attribute if it is defined.
HTMLOutputElement.htmlForRead only: ADOMTokenList reflecting thefor HTML attribute, containing a list of IDs of other elements in the same document that contribute to (or otherwise affect) the calculatedvalue.
HTMLOutputElement.labelsRead only: ANodeList of<label> elements associated with the element.
HTMLOutputElement.name: A string reflecting thename HTML attribute, containing the name for the control that is submitted with form data.
HTMLOutputElement.typeRead only: The string"output".
HTMLOutputElement.validationMessageRead only: A string representing a localized message that describes the validation constraints that the control does not satisfy (if any). This is the empty string if the control is not a candidate for constraint validation (willValidate isfalse), or it satisfies its constraints.
HTMLOutputElement.validityRead only: AValidityState representing the validity states that this element is in.
HTMLOutputElement.value: A string representing the value of the contents of the elements. Behaves like theNode.textContent property.
HTMLOutputElement.willValidateRead only: Returns a boolean value that indicates whether the element is a candidate for constraint validation. Alwaysfalse forHTMLOutputElement objects.

Instance methods

This interface also inherits methods from its parent,HTMLElement.

HTMLOutputElement.checkValidity()

Checks the validity of the element and returns a boolean value holding the check result.

HTMLOutputElement.reportValidity()

This method reports the problems with the constraints on the element, if any, to the user. If there are problems, fires aninvalid event at the element, and returnsfalse; if there are no problems, it returnstrue.

When the problem is reported, the user agent may focus the element and change the scrolling position of the document or perform some other action that brings the element to the user's attention. User agents may report more than one constraint violation if this element suffers from multiple problems at once. If the element is not rendered, then the user agent may report the error for the running script instead of notifying the user.

HTMLOutputElement.setCustomValidity()

Sets a custom validity message for the element. If this message is not the empty string, then the element is suffering from a custom validity error, and does not validate.

Modes

This element behaves in one of two modes:default mode andvalue mode.

Default mode

Initially, the element is in default mode, and so the contents of the element represent both the value of the element and its default value.

If the element is in default mode when the descendants of the element are changed in any way, thedefaultValue property is set to the value of thetextContent property.

Resetting the form puts the element into default mode, and sets thetextContent property to the value of thedefaultValue property.

Value mode

The element goes into value mode when the contents of thevalue property are set. Thevalue property otherwise behaves like thetextContent property. When the element is in value mode, the default value is accessible only through thedefaultValue property.