How to use the API reference

Find the API category

An ng-* HTML name is usually a directive. A name injected into a function is a service or value token. A capitalized TypeScript name is a generated type.

Read a TypeScript signature

value?: string means the property is optional and, when supplied, must be a string. string | null means either value is accepted. () => void means a function takes no arguments and returns no useful value. Array<T> means an array whose items have type T.

Check lifecycle and ownership

Before using an API, determine when it is created, when callbacks run, and who releases listeners or resources. Component, directive, scope, route, and application lifetimes are different.

Prefer the public contract

Use exported package members, documented injection tokens, and generated TypeDoc pages. Names marked internal, generated DOM details, and implementation files are not application contracts.

Return to a guide

Once you find the exact signature, use the linked task or concept page to see the API in an application workflow.