Module TypeScript

Provides classes for working with JavaScript programs, as well as JSON, YAML and HTML.

An anonymous interface type, such as { x: number }.

The predefined any type.

A type that describes a JavaScript Array object.

An array type, such as number[], or in general T[] where T is a type.

A type assertion specifically of the form E as T (as opposed to the <T> E syntax).

A bigint literal as a static type.

A bigint literal used as a TypeScript type annotation.

The predefined bigint type.

The boolean, true, or false type.

The boolean literal type true or false.

A boolean literal used as a type.

The boolean type, internally represented as the union type true | false.

A function or constructor signature in a TypeScript type.

A type that refers to a type variable declared on a class, interface or function.

A type that refers to a class, possibly with type arguments.

A conditional type annotation, such as T extends any[] ? A : B.

A scope induced by a conditional type expression whose extends type contains infer types.

A constructor call signature in a type, that is, a signature with the new keyword.

A constructor type, such as new (x: string) => Object.

A TypeScript enum declaration, such as the following declaration: enum Color { red = 1, green, blue }

A type that refers to the value of an enum member.

A member of a TypeScript enum declaration, such as red in the following declaration: enum Color { red = 1, green, blue }

A scope induced by an enum declaration, containing the names of its enum members.

A type that refers to an enum.

A TypeScript export of form export as namespace X where X is an identifier.

A TypeScript “export-assign” declaration.

An expression with type arguments, occurring as the super-class expression of a class, for example: class StringList extends List<string> In the above example, List is a concrete expression, string is a type annotation, and List<string> is thus an expression with type arguments.

A TypeScript declaration of form declare module "X" {...} where X is the name of an external module.

A require() call in a TypeScript import-equals declaration, such as require("foo") in: import foo = require("foo");

A scope induced by a declaration of form declare module "X" {...}.

A function call signature in a type, that is, a signature without the new keyword.

A TypeScript function type, such as (x: string) => number or a constructor type such as new (x: string) => Object.

A type consisting of a name and at least one type argument, such as Array<number>.

A TypeScript declaration of form declare global {...}.

A TypeScript “import-equals” declaration.

An import used in the context of a namespace inside a type annotation, such as in let x: import("http").ServerRequest.

An import used in the context of a type, such as in let x: import("foo").

An import inside a type annotation, such as in import("http").ServerRequest.

An import used in the context of a variable type, such as in let x: typeof import("fs").

A type of form T[K] where T and K are types.

A type annotation of form infer R.

A TypeScript interface declaration.

A TypeScript interface declaration, inline interface type, or function type.

A scope induced by an interface declaration, containing the type parameters declared on the interface.

A type that refers to an interface, possibly with type arguents.

An inline TypeScript interface type, such as {x: number; y: number}.

An intersection type, such as T & {x: number}.

A type of form S&T, denoting the intersection of type S and type T.

A function return type of form x is T or asserts x is T.

A type of form keyof T where T is a type.

A type that refers to a type variable without a canonical name.

A boolean, number, or string literal type.

A string, number, or boolean literal used as a type.

An identifier that refers to a namespace from inside a type annotation.

An identifier that declares a local name for a namespace, that is, the name of an actual namespace declaration or the local name of an import.

The local name for a namespace in a particular scope.

An identifier that is used as part of a type, such as Date.

The local name for a type in a particular scope.

An identifier that refers to a variable from inside a type.

A type of form { [K in C]: T } where K in C declares a type parameter with C as the bound, and T is a type that may refer to K.

A scope induced by a mapped type expression, containing the type parameter declared as part of the type.

A possibly qualified name that refers to a namespace from inside a type annotation.

A TypeScript namespace declaration.

A statement that defines a namespace, that is, a namespace declaration or enum declaration.

A possibly qualified identifier that refers to or declares a local name for a namespace.

The never type.

A TypeScript expression of form E!, asserting that E is not null.

The null type.

The number type or a number literal type.

A number literal as a static type.

A number literal used as a type.

The predefined number type.

The object type.

An optional type element in a tuple type, such as number? in [string, number?].

A type expression enclosed in parentheses.

An array type such as Array<string>, or equivalently, string[].

A function type that is not a constructor type, such as (x: string) => number.

The symbol type.

A use of the predefined type any, string, number, boolean, null, undefined, void, never, symbol, or object.

A function return type that refines the type of one of its parameters or this.

A type assertion specifically of the form <T> E (as opposed to the E as T syntax).

A type such as Promise<T>, describing a promise or promise-like object.

A qualified name that refers to a namespace from inside a type annotation.

A qualified name that is used as part of a type, such as http.ServerRequest.

A qualified name that refers to a variable from inside a type.

A read-only array type such as ReadonlyArray<string>.

A type of form readonly T, such as readonly number[].

A TypeScript comment of one of the two forms: /// <reference path="FILE.d.ts"/> /// <reference types="NAME"/>

A TypeScript comment of the form: /// <reference path="FILE.d.ts"/>

A TypeScript comment of the form: /// <reference types="NAME" />

A rest element in a tuple type, such as ...string[] in [number, ...string[]].

A satisfies type asserion of the form E satisfies T where E is an expression and T is a type.

A value indicating if a signature is a function or constructor signature.

The string type or a string literal type.

A string literal as a static type.

A string literal used as a type.

The predefined string type.

The symbol type or a specific unique symbol type.

A reference to a global variable for which there is a TypeScript type annotation suggesting that it contains the namespace object of a module.

A template literal used as a type.

A this type in a specific class or interface.

A use of the this type.

A this keyword used as the first operand to an is type.

A tuple type, such as [number, string].

A tuple type such as [number, string].

A static type in the TypeScript type system.

A possibly qualified name that is used as part of a type, such as Date or http.ServerRequest.

A type alias declaration, that is, a statement of form type A = T.

A type that refers to a type alias.

A scope induced by a type alias declaration, containing the type parameters declared the the alias.

A type assertion, also known as an unchecked type cast, is a TypeScript expression of form E as T or <T> E where E is an expression and T is a type.

An identifier declaring a type name, that is, the name of a class, interface, type parameter, or import.

A statement that defines a named type, that is, a class, interface, type alias, or enum declaration.

A type expression, that is, an AST node that is part of a TypeScript type annotation.

A type parameter declared on a class, interface, function, or type alias.

A program element that supports type parameters, that is, a function, class, interface, type alias, mapped type, or infer type.

A possibly qualified identifier that declares or refers to a type.

A type that refers to a class, interface, enum, or enum member.

A folder where TypeScript finds declaration files for imported modules.

A type that refers to a type variable.

The type of a named value, typeof X, typically denoting the type of a class constructor, namespace object, enum object, or module object.

A type of form typeof E where E is a possibly qualified name referring to a variable, function, class, or namespace.

The undefined type.

A union type or intersection type, such as string | number or T & U.

A union or intersection type, such as string|number|boolean or A & B.

A union type, such as string | number.

A union type, such as string|number|boolean.

A unique symbol type.

The predefined unknown type.

A possibly qualified name that refers to a variable from inside a type.

The void type.