laravel exist

1if (User::where('email', $request->email)->exists()) {
2   //email exists in user table
3}
4

1$user = User::where('email', '=', Input::get('email'))->first();
2if ($user === null) {
3   // user doesn't exist
4}

1if (User::where('email', '=', Input::get('email'))->exists()) {
2   // user found
3}

1if($user->isEmpty()){
2    // has no records
3}
4

1$users = User::where('email', '=', $request->input('email'))->first();
2if ($users === null) {
3  // User does not exist
4} else {
5  // User exits
6}