# Validate

The `Validate` class in PHPFast is responsible for validating user input using the **Respect\Validation** library. It provides a collection of methods to check various types of data, such as **strings, numbers, dates, emails, and even JSON or IP addresses**.

This class helps ensure that data meets specific criteria before being processed or stored in a database, reducing errors and improving security.

## Methods in `Validate.php`

### **String & Character Validations**

<pre class="language-php"><code class="lang-php"><strong>// Ensures the string contains only letters (A-Z, a-z).
</strong><strong>public static function alpha() {
</strong>    return RespectValidator::alpha();
}

// Ensures the string contains only numeric digits (0-9).
public static function digit() {
    return RespectValidator::digit();
}

// Ensures the string contains only lowercase letters.
public static function lowercase() {
    return RespectValidator::lowercase();
}

// Ensures the string contains only uppercase letters.
public static function uppercase() {
    return RespectValidator::uppercase();
}
</code></pre>

Example:

```php
Validate::alpha()->validate("hello");         // True
Validate::digit()->validate("1234");          // True
Validate::uppercase()->validate("HELLO");     // True
Validate::lowercase()->validate("Hello");     // False
```

### **Number & Range Validations**

```php
// Ensures the value is a valid number.
public static function NumericVal() {
    return RespectValidator::NumericVal();
}

// Ensures the value falls within a specific range.
public static function between($min, $max) {
    return RespectValidator::between($min, $max);
}
```

Example:

```php
Validate::NumericVal()->validate(25);         // True
Validate::between(10, 50)->validate(30);      // True
Validate::between(10, 50)->validate(5);       // False
```

### **Email, URL, and IP Validations**

```php
// Validates an email format.
public static function email() {
    return RespectValidator::email();
}

// Checks if the value is a valid URL.
public static function url() {
    return RespectValidator::url();
}

// Validates an IP address.
public static function ip() {
    return RespectValidator::ip();
}
```

Example:

```php
Validate::email()->validate("test@example.com");     // True
Validate::url()->validate("https://example.com");    // True
Validate::ip()->validate("192.168.1.1");             // True
Validate::email()->validate("invalid-email");        // False
```

### **Password & Security Validations**

```php
// Ensures the value is not empty.
public static function notEmpty() {
    return RespectValidator::notEmpty();
}

// Ensures the value is exactly equal to another.
public static function equals($compareTo) {
    return RespectValidator::equals($compareTo);
}
```

Exampl&#x65;**:**

<pre class="language-php"><code class="lang-php"><strong>Validate::notEmpty()->validate("password");     // True
</strong>Validate::equals("admin")->validate("admin");   // True
Validate::equals("admin")->validate("user");    // False
</code></pre>

### **JSON, UUID, and Special Format Validations**

```php
// Ensures the string is a valid JSON format.
public static function json() {
    return RespectValidator::json();
}

// Ensures the string is a valid UUID.
public static function uuid() {
    return RespectValidator::uuid();
}

// Validates credit card numbers.
public static function creditCard() {
    return RespectValidator::creditCard();
}
```

Example:

```php
Validate::json()->validate('{"name": "John"}');                     // True
Validate::uuid()->validate("550e8400-e29b-41d4-a716-446655440000"); // True
Validate::creditCard()->validate("4111111111111111");               // True
```

### Validating an Array of Data (`check()`)

* Validates multiple fields based on predefined rules.
* Stores errors for fields that fail validation.

Example:

```php
$data = [
    'username' => 'john_doe',
    'email' => 'invalid-email'
];

$rules = [
    'username' => [
        'rules' => [Validate::alnum(), Validate::length(3, 20)],
        'messages' => ['Username must be alphanumeric.', 'Length must be between 3 and 20 characters.']
    ],
    'email' => [
        'rules' => [Validate::email()],
        'messages' => ['Invalid email format.']
    ]
];

$validator = new Validate();
if (!$validator->check($data, $rules)) {
    print_r($validator->getErrors()); // Output validation errors
}
```