Fix type X is not assignable to type YBest Practices
The error message that undefined cannot be assigned to a specific type often occurs when working with optional parameters. When a parameter is marked as optional, it can either be
undefined or of the specified type. In TypeScript this is represented by a union type such as
undefined | string. If you want to use a function that doesn’t accept
undefined as a parameter (e.g.,
parseInt), you must first validate that your value exists.
Here are some helpful tricks for accomplishing this.Continue reading →