array element wrap all elements

How about array_map?

$links   = array('london', 'new york', 'paris');
$wrapped = array_map(
   function ($el) {
      return "<a href=\"#{$el}\">{$el}</a>";
   },
   $links
);

Demo (Click source)

Without PHP > 5.3, you can't use a lambda function, so you'll need something like this:

function wrap_those_links($el)  { 
      return "<a href=\"#{$el}\">{$el}</a>"; 
}

$links   = array('london', 'new york', 'paris');
$wrapped = array_map('wrap_those_links', $links);

Demo for PHP 5.2 (Again, click Source)

Try join('\n', array_map(function($a) { return "<a href=\"#$a\",>$a<\\a>";}, $links));