Reading data from the array with keys

Question

This code:

$arr1 = array();

for ($i=0; $i<10; $i++)
{
  $arr1[] = array('A'=>rand(0,5), 'B'=>rand(0,4));
}

generates array like this:

[0] array('A'=>0,[B]=>4)
[1] array('A'=>1,[B]=>3)
[2] array('A'=>3,[B]=>1)
//etc.

I need to get the different structure, i.e.:

$arr2 = array('A' => array(0,1,3),'B' => array(4,3,1));

so that later I can use $arr2['A']. If the array is created like it's shown in the first example, then $arr1['A'] will not work.

How can I get $arr2 using FOR loop like for $arr1. Hope I explained myself clear enough.

What have you tried.. Firstly you're only generating 1 random number.. so, what do you think the next step would be? Btw given you have basically answered yourself :) — BugFinder
– BugFinder, Commented Sep 12, 2012 at 10:45
@BugFinder: Sorry, I still don't understand how to get the $arr2 structure from FOR loop. — You Kuper
– You Kuper, Commented Sep 12, 2012 at 10:47

hsz · Accepted Answer · 2012-09-12 10:47:29Z

3

Try with:

$arr2 = array(
  'A' => array(),
  'B' => array()
);

for ($i=0; $i<10; $i++)
{
  $arr2['A'][] = rand(0,5);
  $arr2['B'][] = rand(0,4);
}

If you want to convert existing $arr1 into $arr2, try with:

$arr2 = array(
  'A' => array(),
  'B' => array()
);

foreach ( $arr1 as $value )
{
  $arr2['A'][] = $value['A'];
  $arr2['B'][] = $value['B'];
}

answered Sep 12, 2012 at 10:47

hsz

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