PHP Exercises: Group the elements of an array based on the given function
PHP: Exercise-83 with Solution
Write a PHP program to group the elements of an array based on the given function.
Sample Solution: -
PHP Code:
<?php
// License: https://bit.ly/2CFA5XY
function groupBy($items, $func)
{
$group = [];
foreach ($items as $item) {
if ((!is_string($func) && is_callable($func)) || function_exists($func)) {
$key = call_user_func($func, $item);
$group[$key][] = $item;
} elseif (is_object($item)) {
$group[$item->{$func}][] = $item;
} elseif (isset($item[$func])) {
$group[$item[$func]][] = $item;
}
}
return $group;
}
print_r(groupBy(['one', 'two', 'three', 'four'], 'strlen'));
?>
Sample Output:
Array ( [3] => Array ( [0] => one [1] => two ) [5] => Array ( [0] => three ) [4] => Array ( [0] => four ) )
Flowchart:

PHP Code Editor:
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Previous: Write a PHP program to get the index of the last element for which the given function returns a truth value.
Next: Write a PHP program to check a flat list for duplicate values. Returns true if duplicate values exists and false if values are all unique.
What is the difficulty level of this exercise?
Test your Programming skills with w3resource's quiz.
PHP: Tips of the Day
Returns all elements in an array except for the first one
Example:
<?php function tips_tail($items) { return count($items) > 1 ? array_slice($items, 1) : $items; } print_r(tips_tail([1, 5, 7])); ?>
Output:
Array ( [0] => 5 [1] => 7 )
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