TypeScript's `Pick` and `Omit`

TypeScript’s Pick and Omit are two utility types that allow you to create new types based on existing types. These types can be very useful in creating new types that are more specialized for a specific use case.

Pick

The Pick type allows you to create a new type by selecting only the specified properties from an existing type. Here’s an example:

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type Person = {
  name: string;
  age: number;
  email: string;
};

type PersonNameAndAge = Pick<Person, "name" | "age">;

// PersonNameAndAge is equivalent to:
// {
//   name: string;
//   age: number;
// }

In this example, PersonNameAndAge is a new type that only includes the name and age properties from the Person type. The syntax for using Pick is as follows:

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Pick<Type, Keys>

Here, Type is the type you want to pick properties from, and Keys is a union of the keys you want to include in the new type.

Omit

The Omit type allows you to create a new type by excluding the specified properties from an existing type. Here’s an example:

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type Person = {
  name: string;
  age: number;
  email: string;
};

type PersonWithoutEmail = Omit<Person, "email">;

// PersonWithoutEmail is equivalent to:
// {
//   name: string;
//   age: number;
// }

In this example, PersonWithoutEmail is a new type that includes all the properties from the Person type except for the email property. The syntax for using Omit is as follows:

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Omit<Type, Keys>

Here, Type is the type you want to exclude properties from, and Keys is a union of the keys you want to exclude from the new type.

Cheer! 🍺