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30-seconds-of-code/snippets/reverseNumber.md
Isabelle Viktoria Maciohsek 27c168ce55 Bake date into snippets
2021-06-13 13:55:00 +03:00

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reverseNumber math,string,beginner 2020-07-17T16:41:28+03:00 2020-09-18T21:19:23+03:00

Reverses a number.

  • Use Object.prototype.toString() to convert n to a string.
  • Use String.prototype.split(''), Array.prototype.reverse() and String.prototype.join('') to get the reversed value of n as a string.
  • Use parseFloat() to convert the string to a number and Math.sign() to preserve its sign.
const reverseNumber = n => 
  parseFloat(`${n}`.split('').reverse().join('')) * Math.sign(n);
reverseNumber(981); // 189
reverseNumber(-500); // -5
reverseNumber(73.6); // 6.37
reverseNumber(-5.23); // -32.5