yii2 compare validation

In this example you can see password and password_again attributes comparing using compare and compareAttribute.

Another example is validates if price is greater than or equal to 5000 using the compare and compareAttribute.

Yii2 Compare validation Rules

[
    // validates "password" attribute equals to "password_again"
    ['password', 'compare'],

    // same as above but with explicitly specifying the attribute to compare with
    ['password', 'compare', 'compareAttribute' => 'password_again'],

    // validates if price is greater than or equal to 5000
    ['price', 'compare', 'compareValue' => 5000, 'operator' => '>=', 'type' => 'number'],
]