Making IF ELSE statement with combinations of choice - php

Question

Currently I'm making an application to suggest a car that suits the users' preferences based on their selection. I'd skip the HTML form but the choices are as follow:
Type: MPV, SUV, Sedan
Passengers: 5, 7
Engine: Gasoline, Diesel
Budget: Low, Medium, High, Luxury
Here I'm trying to make a combination because I want that every single choice counts. Therefore this is what I've done so far:
if (isset($_POST['submit'])
{
$type = $_POST['type'];
$passengers = $_POST['passengers'];
$engine = $_POST['engine'];
$budget = $_POST['budget'];
if ($type == 'MPV' && $passengers == 5 && $engine == 'Gasoline' && $budget == 'Low')
{
// execute my function here
}
else if ($type == 'MPV' && $passengers == 7 && $engine == 'Gasoline' && $budget == 'Low')
{
// execute my function here
}
else if ($type == 'MPV' && $passengers == 5 && $engine == 'Diesel' && $budget == 'Low')
{
// execute my function here
}
// and it goes on and on......
I know my problem is I will have to keep making if/elseif function until I list every single possible combination. Now is there any better way to do this? I need to get every single possible combination because there are additional calculations to be done in my custom function.
Here is my custom function:
public function calculateDetails($displacement_bottom, $displacement_top, $price_bottom, $price_top, $clearance)
{
$stmt = $connect->prepare("SELECT id, brand, name FROM cars
WHERE type = '$type'
AND displacement BETWEEN '$displacement_bottom' AND '$displacement_top'
AND price BETWEEN '$price_bottom' AND '$price_top'
AND clearance = '$clearance'
AND passengers = '$passengers'
AND engine = '$engine'
LIMIT BY 3");
$stmt->execute();
while ($row = $stmt->fetch())
{
$result = echo htmlspecialchars($row['brand'])." ".htmlspecialchars($row['name']);
}
return $result;
}
So I can do this
if ($type == 'MPV' && $passengers == 5 && $engine == 'Gasoline' && $budget == 'Low')
{
$suggestion = calculateDetails(1500, 2000, 100, 150, 'Medium');
echo $suggestion;
} else if ($type == 'MPV' && $passengers = 7 && $engine == 'Gasoline' && $budget = 'Low')
{
// continue on and on...
}
Since I couldn't find a way to simplify the if/else "loop" (and I started thinking about giving up :( ), I came into few new functions
public function typeDetails($type)
{
if ($type == 'MPV')
{
$detailed_type = echo "1500 AND 2000";
}
else if ($type == 'SUV')
{
$detailed_type = echo "2000 AND 3500";
}
else
{
$detailed_type = echo "2000 AND 3000";
}
return $detailed_type;
}
public function budgetDetails($budget)
{
if ($budget == 'Low')
{
$detailed_price = echo "100 AND 150";
}
else if ($type == 'Medium')
{
$detailed_price = echo "150 AND 250";
}
else if ($type == 'High')
{
$detailed_price = echo "250 AND 450";
}
else
{
$detailed_price = echo "450 AND 800";
}
return $detailed_price;
}
public function groundClearance($type)
{
if ($type == 'MPV')
{
$ground_clearance = "Medium";
}
else if ($type == 'SUV')
{
$ground_clearance = "High";
}
else
{
$ground_clearance = "Low";
}
return $ground_clearance;
}
In which I hope to be able to do this instead
$type = $_POST['type'];
$budget = $_POST['budget'];
$displacement = typeDetails($type);
$price = budgetDetails($budget);
// same function but with simplified where clause
$suggestion = calculateDetails($displacement, $price, $clearance);
echo $suggestion;
I'm too tired to continue today, but thanks to you guys I came up into few more ideas. I appreciate all the replies and comments given here. I might not be that good in PHP, therefore I want to learn how to make things simpler

Answer 1

There is not much you can do here. As an alternative option, you may create kind of a matrix for your models using multi level array:
$matrix = [
'MPV' => [
'Diesel' => [
5 => [
'Low' => function() { ... },
'Medium' => function() { ... },
],
],
'Gasoline' => [ ... ],
],
'SUV' => [ ... ],
];
if (isset($matrix[$type][$engine][$passengers][$budget])) {
$matrix[$type][$engine][$passengers][$budget]();
}
You may also reuse some functions if they don't differ too much or set special constants instead of functions to be passed to a single custom method. It really depends on the actual functionality you have for each combination.

Answer 2

Well I will pick that your function will be to choose a car, so you can add all options that you have (ex 3 different cars) into your database and have 4 values for each :
Type
Passengers
Engine
Budget
And set default value for each car :
ex for this condition :
$type == 'MPV' && $passengers == 5 && $engine == 'Gasoline' && $budget == 'Low'
Type = 1
Passengers = 1
Engine = 1
Budget = 1
And regarding clients choosing different options, you can filter your query and select the car that match the search !
Ex :
$query = ("SELECT * FROM car WHERE type = :type AND passengers = :passengers AND engine = :engine AND budget = :budget");