javascript check if string is number
// native returns true if the variable does NOT contain a valid number isNaN(num) // can be wrapped for making simple and readable function isNumeric(num){ return !isNaN(num) } isNumeric(123) // true isNumeric('123') // true isNumeric('1e10000') // true (This translates to Infinity, which is a number) isNumeric('foo') // false isNumeric('10px') // false