Remove the first data character and push a string value onto the end of a data representation while preserving its original presentation.

push_char.php

<?php

/**
 * Remove the first data character and push a string value onto the
 * end of a data representation while preserving its original
 * presentation.
 *
 * @param  string $char   A string value that will be concatenated
 *                        to the data series
 * @param  string $string A string representation of data in which
 *                        both data and formatting are derived
 * @return string         A string representation
 */
function push_char($char, $string) {
	// Using regular expressions to define "data" for extraction and
	// abstracting the presentation.
	$pattern = '/\d|\w/';

	// Preserve the template.
	$template = preg_replace($pattern, '%s', $string);

	// Capture data into an array.
	preg_match_all($pattern, $string, $matches);
	$data = $matches[0];

	// Manipulate the data by removing the first item and then
	// appending $char.
	array_shift($data);
	array_push($data, $char);

	// Apply the new data back to our template.
	return vsprintf($template, $data);
}