useHas

Usehas is a term used in software development to describe a pattern, library, or hook that determines whether a particular feature, capability, or condition is present at runtime. There is no single canonical implementation, but useHas commonly refers to a function or hook named useHas that returns a boolean indicating the presence of the specified item.

In modern UI frameworks such as React, useHas is often implemented as a custom hook. It accepts a target—such as a user permission, feature flag, or capability—and returns true when the current context satisfies it. This enables conditional rendering and behavior without scattering checks throughout the codebase. Implementation details vary: some versions accept a predicate function, others accept a string key; many integrate with state management or permission systems and may subscribe to changes.

Usage patterns typically center on access control and feature toggling. For example, a component might render admin controls only if useHas(userPermissions, 'admin') evaluates to true, or a dashboard may show a new layout only when useHas(featureFlags, 'new-dashboard') is active. The approach supports dynamic interfaces that respond to permission updates or feature rollouts without invasive refactoring.

Related concepts include feature flags, capability-based access control, and permission-based rendering. Because useHas is not standardized, developers should consult the documentation of the specific library or framework they are using to understand its exact API, semantics, and reactivity guarantees.