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Never

 In TypeScript, the never type represents the type of values that never occur. It is typically used in two main scenarios:

  1. Function Return Type: When a function never finishes executing (e.g., it always throws an error or enters an infinite loop), TypeScript can infer that the function returns never.


In this example, throwError is a function that explicitly throws an Error. TypeScript infers that this function will never return normally; it will always throw an error. Therefore, the return type is never.

Key Points:

  • Use Case: never is useful for functions that throw errors or enter infinite loops, where the function does not return normally.
  • Inference: TypeScript uses never to narrow down types in conditional type inference and control flow analysis.
  • No Values: Unlike void, which represents the absence of a value, never indicates that a value will never exist (e.g., due to an infinite loop or always throwing an error).

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