Regex Basics

Regular expressions (regex) are a powerful tool used for pattern matching in strings. They are widely used in programming, text processing, and data validation. Here's a brief introduction to the basics of regex.

Syntax

The basic syntax of a regex pattern is quite simple. It consists of characters that match specific patterns. Here are some common regex symbols:

. matches any character except a newline.
* matches zero or more of the preceding element.
+ matches one or more of the preceding element.
? matches zero or one of the preceding element.
[] defines a character class, matching any one of the enclosed characters.
^ asserts the position at the start of a line.
$ asserts the position at the end of a line.

Examples

Here are some examples of regex patterns and their meanings:

a.*b matches any string that starts with 'a' and ends with 'b', with any characters in between.
[a-z] matches any lowercase letter.
^hello matches any line that starts with 'hello'.
world$ matches any line that ends with 'world'.

Resources

For more in-depth learning about regex, you can check out our Regex Tutorial.