TalkPHP - How to search array

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How to search array

I want to code a buy one get one free option on my site. Initially, I wrote it so that half of the number of products were free, based on the lowest prices. So, if three products were $200 each and three were $100 each, the three $100 ones would be free. But my customers quickly pointed out they were not really getting one free. It should have been one $200 and two $100 for free. That's where I am at now. I can't figure out how to determine which ones should be free. Here's some pseudo code showing what I am doing.

PHP Code:


		
			
function IsFree($id) {

Array

(

    [0] => Array

        (

            [id] => 1961

            [price] => 129.0000

            [model] => 20

        )



    [1] => Array

        (

            [id] => 1962

            [price] => 179.0000

            [model] => 24

        )



    [2] => Array

        (

            [id] => 7047

            [price] => 229.0000

            [model] => 30

        )



    [3] => Array

        (

            [id] => 19650

            [price] => 299.0000

            [model] => 30

        )



    [4] => Array

        (

            [id] => 1989

            [price] => 279.0000

            [model] => 36

        )



    [5] => Array

        (

            [id] => 23112

            [price] => 339.0000

            [model] => 36

        )



    [6] => Array

        (

            [id] => 22399

            [price] => 409.0000

            [model] => 40

        )

)

  return true or false;

}



for ($i = 0; $i < count($products); ++$i {

  if (IsFree($products[$i]['id']))

   echo 'Mark as free';

}

The IsFree function reads through the products and creates a multi array sorted on the model and then the price. I just showed the output of that array to, hopefully, make it clearer. If I wanted to just return the half of the products that have the lowest prices, I could just take that many from the beginning of the array. But I need to check whether there are duplicate model sizes listed. If there are, then the lowest price of that pair gets returned instead. I think part of the problem might be that the array is being created each time and the product being checked is a whole new search. In other words, there's no history of what has already been found. I thought of adding another array to track those but that made an already confusing situation worse.

Does anyone have any suggestions on how to tackle this problem?

You mean something like this:

PHP Code:


		
			
<?php



$data = array();

$data[] = array('id'=>1961,'price'=>129.0000,'model'=>20);

$data[] = array('id'=>1962,'price'=>179.0000,'model'=>24);

$data[] = array('id'=>7047,'price'=>229.0000,'model'=>30);

$data[] = array('id'=>19650,'price'=>299.0000,'model'=>30);

$data[] = array('id'=>1989,'price'=>279.0000,'model'=>36);

$data[] = array('id'=>23112,'price'=>339.0000,'model'=>36);

$data[] = array('id'=>22399,'price'=>409.0000,'model'=>40);







function isFree($input) 

{

    $output = array();

    foreach($input as $row)

    {

        if(!array_key_exists($row['model'],$output) || array_key_exists($row['model'],$output) && $output[$row['model']]['price'] < $row['price'] )

        {

            $output[$row['model']] = $row;

        }

    }



    return $output;

} 



echo "Current selected items: \n".print_r($data,true)."\n";

echo "New selected items:\n".print_r(isFree($data),true)."\n";

outputs:

Code:

Current selected items: 

Array

(

    [0] => Array

        (

            [id] => 1961

            [price] => 129

            [model] => 20

        )



    [1] => Array

        (

            [id] => 1962

            [price] => 179

            [model] => 24

        )



    [2] => Array

        (

            [id] => 7047

            [price] => 229

            [model] => 30

        )



    [3] => Array

        (

            [id] => 19650

            [price] => 299

            [model] => 30

        )



    [4] => Array

        (

            [id] => 1989

            [price] => 279

            [model] => 36

        )



    [5] => Array

        (

            [id] => 23112

            [price] => 339

            [model] => 36

        )



    [6] => Array

        (

            [id] => 22399

            [price] => 409

            [model] => 40

        )



)



New selected items:

Array

(

    [20] => Array

        (

            [id] => 1961

            [price] => 129

            [model] => 20

        )



    [24] => Array

        (

            [id] => 1962

            [price] => 179

            [model] => 24

        )



    [30] => Array

        (

            [id] => 19650

            [price] => 299

            [model] => 30

        )



    [36] => Array

        (

            [id] => 23112

            [price] => 339

            [model] => 36

        )



    [40] => Array

        (

            [id] => 22399

            [price] => 409

            [model] => 40

        )



)

Thank you for the code but that doesn't output the result I am looking for. I didn't think about it when I originally posted but I probably should have listed what the output should be, for this example, so I will do that now. Given the following array, there are seven entries, which means there should be three marked as free, since it's buy one get one.

PHP Code:


		
			
$data[] = array('id'=>1961,'price'=>129.0000,'model'=>20); 

$data[] = array('id'=>1962,'price'=>179.0000,'model'=>24); 

$data[] = array('id'=>7047,'price'=>229.0000,'model'=>30); 

$data[] = array('id'=>19650,'price'=>299.0000,'model'=>30); 

$data[] = array('id'=>1989,'price'=>279.0000,'model'=>36); 

$data[] = array('id'=>23112,'price'=>339.0000,'model'=>36); 

$data[] = array('id'=>22399,'price'=>409.0000,'model'=>40);

The three would be:

This one since it is the lowest price and not part of a pair (where a pair refers to items with the same model numbers)

PHP Code:


		
			
$data[] = array('id'=>1961,'price'=>129.0000,'model'=>20);

This one since it is part of a pair and is the lowest of that pair

PHP Code:


		
			
$data[] = array('id'=>7047,'price'=>229.0000,'model'=>30);

This one since it is part of a pair and is the lowest of that pair

PHP Code:


		
			
$data[] = array('id'=>1989,'price'=>279.0000,'model'=>36);

So even though this one

PHP Code:


		
			
$data[] = array('id'=>1962,'price'=>179.0000,'model'=>24);

is lower in price than the last two above it, they take precedence since they are part of a pair.

I just wanted to say that I figured this out. I ended up creating a master array before looping through the products. If a product is found, I then delete it from the master array and count the number of free products found. I have to iterate through the array more times that is probably necessay but it works. Thanks for trying to help.