Check if a string contains only digits

JavaScript

const isNumeric = (str) => !/[^0-9]/.test(str)

TypeScript

const isNumeric = (str: string): boolean => !/[^0-9]/.test(str)

Examples

isNumeric(2) // true
isNumeric('23') // true
isNumeric('00123') // true

isNumeric('1.23') // false
isNumeric('-Infinity') // false
isNumeric('Infinity') // false
isNumeric('NaN') // false