How to properly type a regex when destructuring?

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  How to properly type a regex when destructuring?
  const [a, b, c, d, f, g = ''] = value.match (/ \ d + / g);
  TS swears at Type 'RegExpMatchArray | null 'is not an array type or a string type. Use compiler option '--downlevelIteration' to allow iterating of iterators.

  JavaScript Evan Pope, Jun 9, 2020

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2 Answers
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  Are you sure it won't be null?
  
  If yes, then you can simply report it to the compiler:
  
  

  const [a, b, c, d, f, g= ''] = value.match(/\d+/g)!;

  
  
  
  
  But for good reason, it should be checked for null. At least like this:
  
  

  const [a, b, c, d, f, g= ''] = value.match(/\d+/g) || [];

  Anonymous

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• 0
  Well, it tells you in plain text: match can return null and then an error will occur at runtime.
  
  
  
  Or like this:

  const [a, b, c, d, f, g= ''] = value.match(/\d+/g) || [];

  Or, if you are 146% sure that match will definitely find something:

  const [a, b, c, d, f, g= ''] = value.match(/\d+/g) as string[];

  Isaiah Ingram

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