Last updated
Last updated
Use the match
method
Use capture groups
Use the scan
method
Understand the diff between match
and scan
You've learned the basics of writing Regular Expressions in Ruby. In this lesson we'll learn how to use regular expressions with the match
and scan
ruby methods. We'll also learn to use capture groups.
The scan
method returns an array of all items in your string that match a given Regular Expression. For example:
The match
method returns the first item in your string that matches a given Regular Expression as a MatchData
object. For example:
More often than not, we use the result of the match method as a boolean, indicating the existence of the pattern in the given string.
Grep is an enumerable method for pattern searching in arrays and hashes. Similar to scan
, grep
will return an array of matching items from an array.
Using parentheses in our regex allows us to create 'groups' that we can refer to in our scan/match/grep methods as indexes in an array. In the example below we create three capture groups for the three sets of digits in a phone number. Now, when we scan a list of numbers, each phone number is broken down into subgroups based on the capture groups we built in our regular expressions:
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