30-seconds-of-code/snippets/validateNumber.md

title, tags

title	tags
validateNumber	math,intermediate

Returns true if the given value is a number, false otherwise.

• Use !isNaN() in combination with parseFloat() to check if the argument is a number.
• Use isFinite() to check if the number is finite.
• Use Number() to check if the coercion holds.

const validateNumber = n => !isNaN(parseFloat(n)) && isFinite(n) && Number(n) == n;

validateNumber('10'); // true