test-bold-array.php

<?php
 
function add_b_tags(&$item)
{
    //$item = "<b>$item</b>";

$item = explode(" ", $item);
$r = array();
foreach($item as $i){
	$r[] = "<b>".$i."</b>";
}
$item = implode(" ", $r);
}
 
$arr = array(
        array(
                '4'=>'abcd efgh ijkl',
                '5'=>'mnop qrst uvwx',
                '6'=>'wawa ghgh dfdr',
        ),
        array(
                '14'=>'hfgh fhyj hgjk',
                '15'=>'nana gfjj fggh',
                '16'=>'wafd gjgh jhuh',
        )
);
 
array_walk_recursive($arr, 'add_b_tags');
 
echo "<pre>";
print_r ($arr);
echo "</pre>";
 
$z = array();
foreach($arr as $x => $y)
{
    $i = 0;
    foreach($y as $k => $v)
    {
	if($i == 0)
	{
		$z[$x][$k] = $v;
	}
	else
	{
		$r = explode(' ',$v);
		$z[$x][$k] = end($r);
	}
	$i++;
    }
}
 
echo "<pre>";
print_r ($z);
echo "</pre>";
?>