defaultValue

DefaultValue is a concept and term used across programming to denote a value that is used when no explicit value is supplied. In code, it can refer to a property name, a parameter default, or a database default, depending on the context. The common idea is to provide a fallback that preserves predictable behavior.

In web development, defaultValue often appears as a property that reflects the initial value of a form control. For example, in the DOM, an input element may have a value attribute in HTML, which becomes the defaultValue in scripts. If an user changes the text, the live value (value) may differ from defaultValue. The defaultValue can be reset by form operations or by setting the element’s value back to its defaultValue. For select and textarea elements, a similar concept applies.

In React and other UI libraries, defaultValue is used as a prop to set the initial value of uncontrolled form controls. For example, an input with defaultValue="hello" will render with that initial content, but subsequent edits are managed by the element itself, not by React state. Controlled components, by contrast, use a value prop and onChange handlers rather than defaultValue.

Beyond UI, the term appears in databases as well, where a DEFAULT clause provides a default value for a column when no value is supplied on insert. This usage conveys the same idea of a fallback, even though the syntax and naming differ from defaultValue in programming APIs.

In summary, defaultValue serves as a built-in fallback that preserves expected behavior when explicit input is absent.