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Note that object literals may only specify known properties #2421

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Merged
merged 6 commits into from
May 22, 2023
Merged

Note that object literals may only specify known properties #2421

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71f00d1
Note that object literals may only specify known properties
thisisrandy Jun 13, 2022
faea8e8
Fix typo
thisisrandy May 20, 2023
045b76d
Link to excess property checks docs
thisisrandy May 20, 2023
ab15264
Move link to more relevant part of sentence
thisisrandy May 21, 2023
dbbcdc8
Merge same-subject paragraphs
thisisrandy May 21, 2023
ae7fcd2
Make link relative
thisisrandy May 22, 2023
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12 changes: 10 additions & 2 deletions packages/documentation/copy/en/reference/Type Compatibility.md
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Expand Up @@ -68,9 +68,17 @@ greet(dog); // OK
```

Note that `dog` has an extra `owner` property, but this does not create an error.
Only members of the target type (`Pet` in this case) are considered when checking for compatibility.
Only members of the target type (`Pet` in this case) are considered when
checking for compatibility. This comparison process proceeds recursively,
exploring the type of each member and sub-member.

This comparison process proceeds recursively, exploring the type of each member and sub-member.
Be aware, however, that object literals [may only specify known properties](/docs/handbook/2/objects.html#excess-property-checks).
For example, because we have explicitly specified that `dog` is
of type `Pet`, the following code is invalid:

```ts
let dog: Pet = { name: "Lassie", owner: "Rudd Weatherwax" }; // Error
```

## Comparing two functions

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