Multidimentional Arrays [Creating and Looping for output]

[Adamhumbug]

Hi All,

I have been scouring the internet for a good source that shows how to create an array and loop through it to output it to the page.  I have done this several times but everytime it comes to doing it i have to scratch my head and google to get anywhere near the answer.

I have created a 2 dimentional array of data using the following:

function getExistingAwards(){
	include 'includes/dbconn.php';

	$stmt = $conn -> prepare("SELECT id, award_name, award_year, award_winner from award");
	$stmt -> execute();
	$stmt -> bind_result($id, $an, $ay, $aw);
	$awards = array();
	$out = '';

	while($stmt -> fetch()){
		$awards[$ay] = [$id, $an, $aw]; 
	}
}

This gives me a data structure that looks like this.

Array
(
    [2021] => Array
        (
            [0] => 1
            [1] => Avenue Park Award
            [2] => 1
        )

    [2019] => Array
        (
            [0] => 2
            [1] => Avenue Park Award
            [2] => 1
        )

)

Issue 1 - This looks correct but if there are more than one entries that has the year 2021 for example, only the last one will be added to the array.

Issue 2 - After i have the correct data in the array how do i go about looping through each level of the array. I really struggle with for each loops.

As always, your help is appreciated.

[Barand]

If there are multiple reocords for years then each array element for the year need to be an array of records

while($stmt -> fetch()){
		$awards[$ay][] = [$id, $an, $aw]; 
	}

or

while($stmt -> fetch()){
		$awards[$ay][$id] = [$an, $aw]; 
	}

 

[Adamhumbug]

Perfect answer as always. 

That did of course work, as for getting the data out of the other end, could you lend a hand with that also please?

[kicken]

Your top level array is a list of award years.  Inside each year is a list of winners.  If you want to loop through it all, just use two nested foreach loops.

$awardYearsList = getExistingAwards();
foreach ($awardYearsList as $awardYear => $winnerList){
    echo '<p>Winners in award year '.$awardYear.':</p>';
    foreach ($winnerList as $winner){
        echo '<p>'.$winner[0].' - '.$winner[1].'</p>';
    }
}

 

[Adamhumbug]

Thank you for this.

Using this method, is there anyway for me to reference the keys rather than the position.  So for example when echoing out i could use $id, $ay, $aw?

[kicken]

If you want keys, you need to define them when you create the array.

while($stmt -> fetch()){
	$awards[$ay][$id] = ['an' => $an, 'aw' => $aw]; 
}

Then you can use $winner['an'] / $winner['aw'] instead.

[Adamhumbug]

Thanks for this, didnt know that was a thing.