PHP Multidimensional Array
Multidimensional array is an array whose elements are also arrays.
Here is an example of a two-dimensional array:
<?php
$arr = [[1, 2, 3], [4, 5, 6], [7, 8, 9]];
?>
Here is an example of a three-dimensional array:
<?php
$arr = [[[1, 2], [3, 4]], [5, 6]];
?>
And so on - arrays can have any level of nesting.
How to output an element from a multidimensional array
Let's say we have the following array:
<?php
$arr = [
'boys' => ['John', 'Nick', 'Mike'],
'girls' => ['Mary', 'Natasha', 'Helen'],
];
echo $arr['boys'][0];
?>
Let's output, for example, 'Nick' using our array:
<?php
$arr = [
'boys' => ['John', 'Nick', 'Mike'],
'girls' => ['Mary', 'Natasha', 'Helen'],
];
echo $arr['boys'][1]; // will output 'Nick'
?>
And now let's output 'Helen':
<?php
$arr = [
'boys' => ['John', 'Nick', 'Mike'],
'girls' => ['Mary', 'Natasha', 'Helen'],
];
echo $arr['girls'][2]; // will output 'Helen'
?>
Array iteration example
Let's say we have an array:
<?php
$arr = [[1, 2, 3, 4, 5], [6, 7, 8], [9, 10]];
?>
Let's output all its elements to the screen. To do this, we need to run two loops nested within each other:
<?php
$arr = [[1, 2, 3, 4, 5], [6, 7, 8], [9, 10]];
foreach ($arr as $elem) {
foreach ($elem as $subElem) {
echo $subElem;
}
}
?>
