How can I check a phone number and bring it back to normal with a regular expression?

• 0
  Hello everyone.
  Faced a problem while trying to bring the phone number back to normal.
  Wrote the following function:
  

  function prettifyNumber(inputVal) {
          const prettified = inputVal
            .replace(/\D/g, "")
            .replace(/^7|^8/, "")
            .replace(/(\d{3})(\d{3})(\d{2})(\d{2})/, "+7 ($1) $2-$3-$4");
          return prettified.length === 18 ? prettified : inputVal;
  }

  
  When checking regular numbers, the function works fine, but when you try to check the number "+7 (495) 111-22-2x" (you can substitute any non-number character instead of v), the value is returned as if it were a valid number.
  Why is this happening, given that the very first replace should remove all non-numeric characters?

  JavaScript Autumn Caldwell, Nov 10, 2020

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1 Answers
• 0

  return prettified.length === 18 ? prettified : inputVal;

  
  
  it returns not "as if it were a real number", but the function argument, that is, what you fed him, then back and gives

  Anonymous

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