Creating a php function with predefined values ​​for a parameter

Question

Let's say I have the following method:

public function chooseCar($car) { return 'You chose this car: ' . $car; } 

I need to set specific values ​​so that I can pass selectCar in the $ car argument, for example, let the developer choose between "Mercedes", "BMW" and "Ford", can this be done in php?

Answer 1

You can try to execute the code below.

 public function chooseCar($car) { $predefined_vals = array( 'Mercedes', 'BMW', 'Ford'); if(in_array($car,$predefined_vals)){ return 'You chose this car: ' . $car; }else{ return "undefined values chosen" } } 

Answer 2

I have one approach for this.

In the function itself, create an array.

And check if the parameter is $car in_array ()

 public function chooseCar($car = '') { $allowedCars = array('Mercedes', 'BMW', 'Ford'); if (! in_array($car, $allowedCars)) { return FALSE; } return 'You chose this car: ' . $car; } 

Answer 3

You can check if the parameter is an "acceptable value" as follows:

 var $acceptableCars = [ 'Mercedes', 'BMW', 'Ford']; function chooseCar($car) { if (in_array($car, $acceptableCars)) { return 'You chose this car: ' . $car; } throw new Exception('Not a valid car'); } 

Answer 4

Something like this will help you with a fixed list of available cars:

 <?php class Cars { private $availableCars = ['Merc', 'Ford']; public function chooseCar($car) { if (in_array($car, $this->availableCars)) { return 'You chose this car: ' . $car; } throw new \Exception('Invalid car chosen!'); } } 

Answer 5

As someone suggested, use an enumeration, this way you will be better programmed, and you are sure that your function is called correctly with the car, and not something else:

 class CarBrand extends SplEnum { // No value, then undefined const __default = 1; const MERCEDES = 1; const AUDI = 2; } function chooseCar(CarBrand $car) { if (CarBrand::MERCEDES == $car) { echo "Mercedes.\n"; } elseif (CarBrand::AUDI == $car) { echo "Audi.\n"; } } $car = new CarBrand(CarBrand::MERCEDES); chooseCar($car); 

Answer 6

Under the code below, if you know the types of cars

 public function chooseCar($car) { switch($car) { case 'BMW': return 'You chose this car: ' . $car; break; case 'Ford': return 'You chose this car: ' . $car; break; default: return 'Soory, Your car not exist in the list'; } } 

You can also use the php in_array () or array_search () functions, as described in other answers.