docs/validators/Undef.md
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
Undef::TEMPLATE_STANDARD| Mode | Template |
|---|---|
default | {{subject}} must be undefined |
inverted | {{subject}} must be defined |
| Placeholder | Description |
|---|---|
subject | The validated input or the custom validator name (if specified). |
| Version | Description |
|---|---|
| 3.0.0 | Renamed to Undef and changed the behavior |
| 1.0.0 | Created as NotOptional |