Naming Keys in a Multidimensional Array in PHP

Question

I have data from a csv file that I organized into a multidimensional array using the following method:

$handle = fopen("bankdata.csv", "r");

while(($data = fgetcsv($handle, 0 ,",")) !==FALSE) {

    $transactions[] = $data;

 }

The array now looks something like this:

Array
(
[0] => Array
    (
        [0] => 2000
        [1] => paycheck
        [2] => credit
    )

[1] => Array
    (
        [0] => 75
        [1] => grocery
        [2] => debit
    )

[2] => Array
    (
        [0] => 45
        [1] => gas
        [2] => debit
    )

[3] => Array
    (
        [0] => 900
        [1] => investments
        [2] => credit
    )

[4] => Array
    (
        [0] => 1500
        [1] => bonus
        [2] => credit
    )

Now I would like to name the keys in each nested array. I thought I would create a new multidimensional array with an equal amount of nested arrays, their values being the intended name of the keys I would like to add to the original array, then do 'array_combine':

$names = array('amount','source','type');

$run = 1;

while($run < 6){
  $run = $run +1;  
  $names2[] = $names;   
}

$combine = array_combine($names2, $transactions);

symcbean · Accepted Answer · 2013-08-19 21:08:15Z

1

You could use array combine:

$keynames=array('amount','source','type');
foreach ($transactions as $i=>$row) {
   $transactions[$i]=>array_combine($keynames, $row);
}

The right way to solve the problem is not to read the the data into an array then transform it - transform it as you read it.

while(($data = fgetcsv($handle, 0 ,",")) !==FALSE) {
    $transactions[]=array_combine($keynames, $data);
}

BTW PHP doesn't do multi-dimensional arrays - they're nested. Despite what it says in the manual, they only emulate multi-dimensional arrays.

answered Aug 19, 2013 at 21:08

symcbean

48.4k6 gold badges64 silver badges99 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

MisterBla Over a year ago

Your solution is likely much better than mine, more efficient too.

Noam Over a year ago

Perfect Thank you. BTW what's the difference between an "emulation" and the real thing?

symcbean Over a year ago

Emulation? For most intents and purposes it will behave like a multi-dimensional array but sparse arrays will use less space - are not constrained to any pre-defined dimensions and unset values behave differently from null values.

MisterBla · Accepted Answer · 2013-08-19 21:09:29Z

Try the following:

$arr = array(
    array(2000, 'paycheck', 'credit'),
    array(75, 'grocery', 'debit'),
    array(45, 'gas', 'debit'),
    array(900, 'investments', 'credit'),
    array(1500, 'bonus', 'credit')
);

$keys = array('amount','source','type');

// $a will make a reference to the array within $arr
// and override the array
foreach($arr as &$a)
{
    // Override the array keys
    $a = array_combine($keys, $a);
}

/* Output:
Array
(
    [0] => Array
        (
            [amount] => 2000
            [source] => paycheck
            [type] => credit
        )

    [1] => Array
        (
            [amount] => 75
            [source] => grocery
            [type] => debit
        )

    [2] => Array
        (
            [amount] => 45
            [source] => gas
            [type] => debit
        )

    [3] => Array
        (
            [amount] => 900
            [source] => investments
            [type] => credit
        )

    [4] => Array
        (
            [amount] => 1500
            [source] => bonus
            [type] => credit
        )

)
*/

Collectives™ on Stack Overflow

Naming Keys in a Multidimensional Array in PHP

2 Answers 2

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related