class Length

LengthConstraint.php in drupal/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/LengthConstraint.php

Contains \Drupal\Core\Validation\Plugin\Validation\Constraint\LengthConstraint.

LengthValidatorTest.php in drupal/core/vendor/symfony/validator/Symfony/Component/Validator/Tests/Constraints/LengthValidatorTest.php

file.schema.yml in drupal/core/modules/file/config/schema/file.schema.yml

drupal/core/modules/file/config/schema/file.schema.yml

class Length extends Constraint {
  public $maxMessage = 'This value is too long. It should have {{ limit }} character or less.|This value is too long. It should have {{ limit }} characters or less.';
  public $minMessage = 'This value is too short. It should have {{ limit }} character or more.|This value is too short. It should have {{ limit }} characters or more.';
  public $exactMessage = 'This value should have exactly {{ limit }} character.|This value should have exactly {{ limit }} characters.';
  public $max;
  public $min;
  public $charset = 'UTF-8';
  public function __construct($options = null) {
    if (null !== $options && !is_array($options)) {
      $options = array(
        'min' => $options,
        'max' => $options,
      );
    }
    parent::__construct($options);
    if (null === $this->min && null === $this->max) {
      throw new MissingOptionsException(sprintf('Either option "min" or "max" must be given for constraint %s', __CLASS__), array(
        'min',
        'max',
      ));
    }
  }

}