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InstanceType<T>

Constructs the instance type produced by a constructor function type T.

Since TS 2.8 Spec ↗

Syntax

InstanceType<Type>

Returns

type — The type of the instance created by calling the constructor T with new.

Examples

class Logger {
  log(msg: string) {}
}

type L = InstanceType<typeof Logger>;
const l: L = new Logger();

function factory<T extends new () => any>(Ctor: T): InstanceType<T> {
  return new Ctor();
}

Notes

Pass a constructor type, usually `typeof SomeClass`. Uses `infer` over a `new (...args: any) => infer R` pattern. Pair with `ConstructorParameters` to build generic factory helpers.

See also