# Possible mistake in 17- Interfaces vs Types

**URL:** <https://forum.codewithmosh.com/t/possible-mistake-in-17-interfaces-vs-types/16633>\
**Category:** TypeScript\
**Created:** [November 23, 2022, 9:16pm UTC](https://forum.codewithmosh.com/t/possible-mistake-in-17-interfaces-vs-types/16633 "2022-11-23T21:16:25Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![groppo91](https://avatars.discourse-cdn.com/v4/letter/g/cdc98d/32.png) [@groppo91](https://forum.codewithmosh.com/u/groppo91)\
**Post date:** [November 23, 2022, 9:16pm UTC](https://forum.codewithmosh.com/t/possible-mistake-in-17-interfaces-vs-types/16633/1 "2022-11-23T21:16:25Z")

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It says  
A class can also implement an interface or a type alias:  
class MyCalendar extends MyInterface {}  
class MyCalendar extends MyType {}

However, I am under the impression from your tutorial in (16-interfaces) you can only implement an interface?

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**Author:** ![k\_rollo](https://avatars.discourse-cdn.com/v4/letter/k/a698b9/32.png) [@k\_rollo](https://forum.codewithmosh.com/u/k_rollo)\
**Post date:** [January 29, 2024, 12:21am UTC](https://forum.codewithmosh.com/t/possible-mistake-in-17-interfaces-vs-types/16633/2 "2024-01-29T00:21:14Z")

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I had the same question just now - [[OOP - Lesson 17] Why is the extends keyword used here?](https://forum.codewithmosh.com/t/oop-lesson-17-why-is-the-extends-keyword-used-here/24816/1)

It’s a shame @Mosh does not really participate in the forums for clarifications.