.setAttribute()

void Element.setAttribute(String name, String value)

Set the value of an attribute.

element.setAttribute(name, value);

Sets the attribute name of element to value.

Note: Attributes differ from properties on an element. A property is simply a property on the object, which can hold any type, while an attribute is always a string. For a variety of interactive properties, such as checked or value of an input, you probably want to simply set the property, eg. checkboxElement.checked = true; or inputElement.value = newValue;.

See also: .getAttribute()

Example

HTML:

<input type="checkbox">

JavaScript:

let value = document.query("input").setAttribute("type", "text");

Resulting HTML:

<input type="text">