validation run only if required laravel code example

Example 1: laravel validator make custom message

$rules = [
        'name' => 'required',
        'email' => 'required|email',
        'message' => 'required|max:250',
    ];

    $customMessages = [
        'required' => 'The :attribute field is required.'
    ];

    $this->validate($request, $rules, $customMessages);

Example 2: laravel unique validation

/**
 * Store a new blog post.
 *
 * @param  Request  $request
 * @return Response
 */

public function store(Request $request)
{
    $validatedData = $request->validate([
        'title' => 'required|unique:posts|max:255',
        'body' => 'required',
    ]);

    // The blog post is valid...
}