Tricks I wish I knew when I learned TypeScript

Re:Tricks I wish I knew when I learned TypeScript by otrahuevada on Tuesday October 12, 2021 @08:13AM (#28838760)

I'm having some trouble finding your proposal in the thread... how would you do it?

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Re:Tricks I wish I knew when I learned TypeScript by jwalton on Tuesday October 12, 2021 @10:37AM (#28840223)

:) Fair enough:

    function isHuman(obj: unknown): obj is Human {
      return !!obj && 
        typeof obj === 'object' &&
        typeof (obj as any).name === 'string' &&
        typeof (obj as any).age === 'number';
    }

This checks the shape of the object, and returns true if it's a `Human`. This will work for array or objects or classes or anything.

[ Parent | on HN ]