Scenario:
<?php
$items = ['Item 1', 'Item 2', 'Item 3'];
$index = 0 ;
print "<ul>";
foreach( $items as $item ) {
print '<li class="'. ( $index % 2 ? 'even' : 'odd') .'">' . $item . '</li>';
$index++;
}
print "</ul>";
?>
You can cleanup the code more or use the array key to detect odd/even. For more than 2 class names or other cases where you want to do some cyclic operation there is no simple way. In Ruby they have cycle function that cycles through items. Twig & Smarty introduced cycle for class names.
With PHP5 closure and Functional programming you can build a reusable solution:
<?php
/**
* Cycle Function that rotates
*/
function cycle( $arr ) {
return function() use(&$arr){
$arr[] = array_shift($arr);
return end($arr);
};
}
$items = ['Item 1', 'Item 2', 'Item 3'];
$cycle = cycle(['odd','even']);
print "<ul>";
foreach( $items as $item ) {
print '<li class="'. $cycle() .'">' . $item . '</li>';
}
print "</ul>";
?>
This time I am cycling through functions, maybe you could find its usage.
<?php
function cycle( $arr ) {
return function( $item ) use(&$arr){
$arr[] = array_shift($arr);
$fn = end($arr);
return $fn( $item );
};
}
$items = ['Item 1', 'Item 2', 'Item 3'];
$cycle = cycle([
function($item){ return strtoupper( $item ); },
function($item){ return ucfirst( $item ); }
]);
print "<ul>";
foreach( $items as $item ) {
print '<li>' . $cycle($item) . '</li>';
}
print "</ul>";
?>
If you have a better alternate plz share your thoughts.
My Findings 