isNumeric

Checks if a string contains only numeric characters.

isNumeric

Signature

function isNumeric(str: string): boolean

Parameters

• str - The string to check

Returns

true if the string contains only digits, false otherwise.

Examples

import { isNumeric } from 'strio'

// Digits only
isNumeric('123')
// true

isNumeric('0')
// true

isNumeric('999999')
// true

// Not numeric
isNumeric('12.34')
// false (decimal point)

isNumeric('12,34')
// false (comma)

isNumeric('-123')
// false (negative sign)

isNumeric('+123')
// false (plus sign)

isNumeric('1 2 3')
// false (spaces)

isNumeric('')
// false (empty)

Use Cases

import { isNumeric } from 'strio'

// Phone number validation
function validatePhoneDigits(phone: string): boolean {
  const digits = phone.replace(/\D/g, '')
  return isNumeric(digits) && digits.length === 10
}

// ID validation
function validateId(id: string): boolean {
  return isNumeric(id) && id.length > 0
}

// Safe number conversion
function toNumber(str: string): number | null {
  return isNumeric(str) ? parseInt(str, 10) : null
}

Related Functions

• isAlpha - Check if alphabetic
• isAlphaNumeric - Check if alphanumeric
• count - Count occurrences

See Also

• String Validation Guide
• API Reference