A regular expression, often abbreviated as regex or regexp, is a concise and flexible sequence of characters that defines a search string pattern. It is a powerful tool used in text processing, enabling you to describe and match complex patterns within strings.
Regular expressions are employed for tasks such as searching, validating, and manipulating text data. By specifying a set of rules or patterns, you can efficiently perform tasks like finding specific strings, validating input formats, or replacing text based on predefined criteria. In essence, regular expressions provide a versatile and compact way to express and execute pattern-based searches in textual data.
<?php
$exp = "/learncoding/i";
?>Note: / is a delemiter, learncoding is being searched an i stand for case-insensitive search.
<?php
$string = "The quick brown fox"'
$pattern = "/quick/";
echo perg_match($pattern, $string); // 1
?>