This is a simple guide on the basics of regular expressions.

# Basics

Use Regex101 or else you will have hell to pay
. - This matches any character. TIO
The quick brown fox jumped over the lazy dog.
t - Matches the character t. This works with most other characters, however some are reserver for tokens.
The quick brown fox jumped over the lazy dog.
[ab] - Matches either a or b.
The quick brown fox jumped over the lazy dog.
[a-f] - Matches any character from a to f in unicode (in this case a, b, c, d, e, f).
The quick brown fox jumped over the lazy dog.
[^a-f] - Matches any character EXCEPT a to f.
The quick brown fox jumped over the lazy dog.

# Quantifiers

Get an amount of something.
* - Matches between 0 and ∞ of something.
? - Matches between 0 and 1 of something.
+ - Matches between 1 and ∞ of something.
{n} - Matches n of something.
{n,} - Matches between n and ∞ of something.
{n,m} - Matches between n and m of something.

# Lookaheads / Lookbehinds

The "if" statements of regex.

## Example

An example of a positive lookahead.
.(?= )
The quick brown fox jumped over the lazy dog.

## Doc

.(?=n) - Any character that is succeeded by n.
.(?!=n) - Any character that is NOT succeeded by n.
(?<=n). - Any character that is preceeded by n.
(?<!n). - Any character that is NOT preceeded by n.

# Tokens

I still need to make this. I might sometime soon, but I'm lazy.

# Flags

I still need to make this. I might sometime soon, but I'm lazy.

# Anchors

I still need to make this. I might sometime soon, but I'm lazy.