@typescript-eslint/eslint-plugin
Version:
TypeScript plugin for ESLint
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---
description: 'Disallow type arguments that are equal to the default.'
---
> 🛑 This file is source code, not the primary documentation location! 🛑
>
> See **https://typescript-eslint.io/rules/no-unnecessary-type-arguments** for documentation.
Type parameters in TypeScript may specify a default value.
For example:
```ts
function f<T = number>(...) {...}
```
It is redundant to provide an explicit type parameter equal to that default: e.g. calling `f<number>(...)`.
This rule reports when an explicitly specified type argument is the default for that type parameter.
<!--tabs-->
```ts
function f<T = number>() {}
f<number>();
```
```ts
function g<T = number, U = string>() {}
g<string, string>();
```
```ts
class C<T = number> {}
new C<number>();
class D extends C<number> {}
```
```ts
interface I<T = number> {}
class Impl implements I<number> {}
```
```ts
function f<T = number>() {}
f();
f<string>();
```
```ts
function g<T = number, U = string>() {}
g<string>();
g<number, number>();
```
```ts
class C<T = number> {}
new C();
new C<string>();
class D extends C {}
class D extends C<string> {}
```
```ts
interface I<T = number> {}
class Impl implements I<string> {}
```