regex.md

Regular expression are used for many things. It whould be complex to write code to check validation.

There is two part:

• The string to search in
• The regular expression
• Regular erxpression starts and end with a //
• The operator OR is |
• It can matches letter or number or special character
• There are used mainly for validation, searching, formatting
• Repeat a pattern /ar+ , the plus operator repeat the letter until there is no more of it.
• james and jameasson
• A chartacter set is [a-z], match one character from a to z
• /[a-z]+/i i operator is a modifier saying don't care about the case
• How to deal with white space \s it stands for tabs, space and almost everything.
• /[a-z0-9\s]+/i
• \w is the same as [a-zA-Z0-9] ``