respect-validation/docs/validators/Undef.md
Henrique Moody d2198dfd01
Replace isValid() calls with assert()
There's more value on showing how `assert()` displays the validation
messages than simply showing if `isValid()` returns `true` or `false`.

However, that increases the chances of having outdated documentation, so
I created a doc linter that updates the Markdown files with the
correct message.
2026-01-13 23:37:06 -07:00

2.1 KiB

Undef

  • Undef()

Validates if the given input is undefined. By undefined we consider null or an empty string ('').

We recommend you to check Comparing empty values for more details.

v::undef()->assert('');
// Validation passes successfully

v::undef()->assert(null);
// Validation passes successfully

Other values similar to undefined values are considered defined:

v::undef()->assert([]);
// → `[]` must be undefined

v::undef()->assert(' ');
// → " " must be undefined

v::undef()->assert(0);
// → 0 must be undefined

v::undef()->assert('0');
// → "0" must be undefined

v::undef()->assert('0.0');
// → "0.0" must be undefined

v::undef()->assert(false);
// → `false` must be undefined

v::undef()->assert(['']);
// → `[""]` must be undefined

v::undef()->assert([' ']);
// → `[" "]` must be undefined

v::undef()->assert([0]);
// → `[0]` must be undefined

v::undef()->assert(['0']);
// → `["0"]` must be undefined

v::undef()->assert([false]);
// → `[false]` must be undefined

v::undef()->assert([[''], [0]]);
// → `[[""], [0]]` must be undefined

v::undef()->assert(new stdClass());
// → `stdClass {}` must be undefined

Templates

Undef::TEMPLATE_STANDARD

Mode Template
default {{subject}} must be undefined
inverted {{subject}} must be defined

Template placeholders

Placeholder Description
subject The validated input or the custom validator name (if specified).

Categorization

  • Miscellaneous

Changelog

Version Description
3.0.0 Renamed to Undef and changed the behavior
1.0.0 Created as NotOptional

See also: