Page 132 - HTML5

Chapter 31: Output Element

Parameters

Attribute Description

Attributes that are available to any HTML5 element. For comprehensive
Global
documentation of these attributes see: MDN Global Attributes

A string representing the name of an output. As a form element, output can be
name referenced by it's name using the document.forms property. This attribute is also
used for collecting values on a form submit.

A space separated list of form element ids (e.g. <inputs id="inp1"> for value is
for
"inp1") that the output is meant to display calculations for.

A string representing the <form> that is associated to the output. If the output is
form actually outside the <form>, this attribute will ensure that the output still belongs to
the <form> and subject to collections and submits of said <form>.

Examples

Output Element Using For and Form Attributes

The following demo features an <output> element's use of the [for] and [form] attributes. Keep
in mind, <output> needs JavaScript in order to function. Inline JavaScript is commonly used in
forms as this example demonstrates. Although the <input> elements are type="number", their value
s are not numbers, they are text. So if you require the values to be calculated, you must
convert each value into a number using methods such as: parseInt(), parseFloat(), Number(), etc.

Live Demo

<!--form1 will collect the values of in1 and in2 on 'input' event.-->
<!--out1 value will be the sum of in1 and in2 values.-->

<form id="form1" name="form1" oninput="out1.value = parseInt(in1.value, 10) +
parseInt(in2.value, 10)">

<fieldset>

<legend>Output Example</legend>

<input type="number" id="in1" name="in1" value="0">
<br/>
+
<input type="number" id="in2" name="in2" value="0">

</fieldset>

</form>

<!--[for] attribute enables out1 to display calculations for in1 and in2.-->
<!--[form] attribute designates form1 as the form owner of out1 even if it isn't a
descendant.-->

https://riptutorial.com/ 116