Basic Array Referencing Php - php

Question

How can I reference the following dynamic arrays' elements ?
$log = array();
$arr1 = array ('a'=>'6:16pm','b'=>2,'c'=>3,'d'=>4,'e'=>5);
$arr2 = array ('a'=>'6:24pm','b'=>20,'c'=>30,'d'=>40,'e'=>50);
$log = array_merge($log, array($arr1['a']=>$arr1));
$log = array_merge($log, array($arr2['a']=>$arr2)); //<-- to use time as key
print_r($log);
for ($x = 0; $x < count($log); $x++) {
print_r ($log[0][$x]['a']); // <-- referencing issue Undefined offset: 0 .. line 20
}
//------ produces
Array
(
[6:16pm] => Array
(
[a] => 6:16pm
[b] => 2
[c] => 3
[d] => 4
[e] => 5
)
[6:24pm] => Array
(
[a] => 6:24pm
[b] => 20
[c] => 30
[d] => 40
[e] => 50
)
)
I'm pretty sure it has something to do with the way I'm naming the $log main array.. and there's probably a better way to do what I wish(.. add/ new elements to $log using the time key) - Still a php noob unfortunately. Thanks for any pointers.

Answer 1

It's a little unclear, but just create an array from the two and use the a index:
$log = array($arr1, $arr2);
foreach($log as $values) {
echo $values['a']; // 6:16pm
}
Or if you want the time as the index, then re-index on a:
$log = array($arr1, $arr2);
$log = array_column($log, null, 'a');
foreach($log as $time => $values) {
echo $time; // 6:16pm
echo $values['b']; // 2
}
It's prettier, but there is no need for the time as the index unless you are going to use ksort or access by index:
echo $log['6:16pm']['b'];

Answer 2

in cases that you don't know your key is recommended that you use foreach statement:
$logs = array();
$arr1 = array ('a'=>'6:16pm','b'=>2,'c'=>3,'d'=>4,'e'=>5);
$arr2 = array ('a'=>'6:24pm','b'=>20,'c'=>30,'d'=>40,'e'=>50);
$logs = array_merge($logs, array($arr1['a']=>$arr1));
$logs = array_merge($logs, array($arr2['a']=>$arr2)); //<-- to use time as key
$logs = array();
$arr1 = array('a' => '6:16pm', 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5);
$arr2 = array('a' => '6:24pm', 'b' => 20, 'c' => 30, 'd' => 40, 'e' => 50);
$logs = array_merge($logs, array($arr1['a'] => $arr1));
$logs = array_merge($logs, array($arr2['a'] => $arr2)); //<-- to use time as key
foreach ($logs as $time => $log) {
//index:
print_r($time);
//array:
print_r($log);
// a array key:
print_r($log['a']);
//go through all keys:
foreach ($log as $letter => $value) {
//index:
print_r($letter);
//value: a
print_r($value);
}
}

Answer 3

You can not call array like
print_r ($log[0]);
Because your array has key. which is 6:16pm for first one and 6:24pm for second. you have to call it by key name you have assigned. your array should be called like this in everywhere even in loop
print_r ($log["6:16pm"]);