respect-validation/docs/08-comparable-values.md

Comparable values

For certain types you can't make comparisons out of the box in PHP but Validation brings support to a few of them.

You can make comparison with the following data types:

• Countable: any object that implements Countable interface
• DateTimeInterface
• Numeric types
• Single character string
• Primitive types in general: normal operation comparison made by PHP
• Time string: date and time format that can be parsed by PHP

Below you can see some examples:

v::greaterThanOrEqual(100)->isValid($collection); // true if it has at least 100 items

v::dateTime()
    ->between(new DateTime('yesterday'), new DateTime('tomorrow'))
    ->isValid(new DateTime('now')); // true

v::numericVal()->lessThanOrEqual(10)->isValid(5); // true

v::stringVal()->between('a', 'f')->isValid('d'); // true

v::dateTime()->between('yesterday', 'tomorrow')->isValid('now'); // true