1--TEST--
2Test preg_replace_callback() function : basic functionality
3--FILE--
4<?php
5/*
6* proto string preg_replace(mixed regex, mixed replace, mixed subject [, int limit [, count]])
7* Function is implemented in ext/pcre/php_pcre.c
8*/
9/*
10* Basic test for preg_replace_callback
11*/
12$replacement = array('zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine'); //array will have the default key values (0-9) and each value is the corresponding key written in words.
13function integer_word($matches) {
14    global $replacement;
15    return $replacement[$matches[0]]; //all examples will be looking for an integer value, if one is found it will be stored in $matches[0] which corresponds to a key in the $replacements array
16
17}
18$subject1 = 'there are 7 words in this sentence.';
19$new_subject1 = preg_replace_callback('/\d/', "integer_word", $subject1);
20print "$new_subject1 \n";
21$subject2 = '1 2 3 4 is now written in words';
22$new_subject2 = preg_replace_callback('/\d/', "integer_word", $subject2, 3); //limits to three replacements
23print "$new_subject2 \n";
24$subject3 = 'there are no numbers in this string';
25$new_subject3 = preg_replace_callback('/\d/', "integer_word", $subject3, 5, $count); //limites to five replacements and counts the number of replacements made ands stores in $count variable
26print "$new_subject3 \n";
27print $count;
28?>
29--EXPECTF--
30there are seven words in this sentence.
31one two three 4 is now written in words
32there are no numbers in this string
330
34