パターンマッチングのための正規表現

A regular expression, or regex, is a compact pattern that describes a set of strings. Automation platforms use regex to find, extract, replace, or validate text.

It is like a search query on steroids — far more flexible than simple find-and-replace.

Incoming data is often messy. Regex helps you:

• Pull an order number out of an email subject
• Validate that a field looks like an email address
• Strip unwanted characters from a string

It turns unstructured text into clean, usable data.

The simplest regex is just the text you want to match. The pattern cat matches the letters c, a, t in sequence.

Most characters in a regex match themselves literally — the power comes from special symbols added on top.

Square brackets define a set of allowed characters. The pattern with a class like a digit class matches any single digit from 0 to 9.

Shorthand classes exist too: backslash d for a digit, backslash w for a word character, backslash s for whitespace.

Quantifiers say how many times something repeats:

• A plus sign means one or more
• A star means zero or more
• A question mark means optional, zero or one
• Braces like 3 mean an exact count

So a digit class followed by plus matches one or more digits.

Anchors tie a pattern to a position rather than a character. The caret matches the start of a string, and the dollar sign matches the end.

Anchoring ensures the whole value matches, not just a piece of it — useful for validation.

Parentheses create a capturing group — a piece of the match you can extract separately. For example, capturing the number inside Order #1234 lets you pull out just 1234.

Groups are how regex extracts structured data from text.

A simple email pattern combines these ideas: word characters, an at sign, more word characters, a dot, and letters. It validates that a string roughly looks like an address.

Real-world email regex can be elaborate, but a basic one catches most cases.

Beyond matching, regex powers smart replacements. You can strip all non-digit characters from a phone number, or reformat a date by capturing its parts and rearranging them.

This is far more flexible than replacing fixed strings.

Zapier, Make, and similar tools expose regex through text-formatting steps or functions like match and replace. You paste the pattern, point it at a field, and use the captured output downstream.

No coding environment needed — just the pattern itself.

Regex is powerful but can bite:

• Test patterns on sample data before deploying
• Special characters like dot and plus need escaping when taken literally
• Overly greedy patterns may match more than intended
• Keep patterns readable; comment what they do

Test your understanding of regular expressions.

You learned regular expressions for pattern matching:

• Regex describes text patterns for finding, extracting, and validating data
• Use character classes, quantifiers, and anchors to build patterns
• Capturing groups extract specific parts of a match
• Apply regex in text-formatting steps for matching and replacing
• Always test patterns and escape special characters

Regex is a powerful tool for taming messy text in your automations.