isBlank

Checks if a string is blank — empty or contains only whitespace characters. null and undefined are considered blank and return true.

Uses String.prototype.trim() internally, which covers all ECMAScript whitespace: standard ASCII whitespace (\t, \n, \r, \f, \v), non-breaking space (U+00A0), BOM (U+FEFF), and all Unicode “Space_Separator” category characters (en space, em space, thin space, ideographic space, etc.).

Zero-width characters (U+200B zero-width space, U+200C, U+200D, U+2060) are not treated as whitespace — they are Unicode “Format” (Cf) characters, not spaces. Strip them explicitly if needed: isBlank(value.replace(/[​-‍⁠]/g, ''))

Available since v2.0.3

Import

import { isBlank } from '@helpers4/string';

Signature

isBlank(value: string | null | undefined): boolean

Parameters

Parameter	Type	Description
value	string | null | undefined	The string to check

Returns

boolean — true if the string is empty, contains only whitespace, or is null/undefined

Examples

Detect empty or whitespace-only strings

Returns true for "" and for any string made entirely of whitespace — including non-breaking space (U+00A0), en/em spaces, ideographic space, and BOM.

isBlank('')      // => true
isBlank('   ')   // => true
isBlank('\t\n')  // => true
isBlank(' ')     // => true   (non-breaking space U+00A0)
isBlank('foo')   // => false
isBlank(' x ')   // => false

Form validation — reject blank input

Use isBlank to reject fields that contain only whitespace.

function validateName(name: string): string | null {
  if (isBlank(name)) return 'Name is required';
  return null;
}
validateName('')    // => 'Name is required'
validateName('   ') // => 'Name is required'
validateName('Ada') // => null

Source

View source on GitHub