Type Union & Intersection in Typescript

 In TypeScript, intersection (&) and union (|) are two different ways to combine types, and they have opposite purposes:

Intersection (&):

Purpose: An intersection type represents a type that has all the properties and methods that are common to all the types being intersected.

Usage: It is used when you want to create a new type that includes all properties and methods from multiple types.

Example:

type TypeA = { propA: number };

type TypeB = { propB: string };

type IntersectionType = TypeA & TypeB;

// IntersectionType contains propA and propB.

Union (|):

Purpose: A union type represents a type that can be one of several types. It allows a value to have a variety of types at different times.

Usage: It is used when a value can have multiple possible types, and you want to express that flexibility.

Example:

type TypeA = { propA: number };

type TypeB = { propB: string };

type UnionType = TypeA | TypeB;

// UnionType can be either TypeA or TypeB.

In summary:

Intersection (&) combines types to create a type that has all properties and methods common to all of them. It narrows down the possibilities to a more specific type.

Union (|) combines types to create a type that can be one of the specified types. It broadens the possibilities to a more flexible type.

These two concepts are often used in different scenarios based on the desired behavior of the types you are working with.