Regular Expressions

Regular expressions (regex) are a syntax to write match patterns to search in strings. You can use regex patterns in many areas of Refine. Wrap the regex pattern in forward slashes /.

Regexr is a good site for learning about regex and testing your patterns. Refine’s regex is based in Java, so you can check the Java regular expression tutorial details.

Find and Match

The functions find(s, p) (creates array of substrings that match the pattern) and match(s, p) (creates array of all capturing groups found by the pattern) are designed specifically for handling regex pattern matching. Here are some examples to compare different uses of the regex:

value	“The dogs”	“Theology”	“Cat food”
value.replace(/^The /,"")	“dogs”	“Theology”	“Cat food”
value.match("^(The )?(.*)")	[ “The “, “dogs” ]	[ null, “Theology” ]	[ null, “Cat food” ]
value.find(/^T\w*/)	[ “The” ]	[ “Theology” ]	[ ]

Note that match takes the regex pattern in quotes, unlike other uses where it is wrapped in forward slashes.

Examples

• In regex ^ is start of string and $ means end of string.
  • Remove “The “ from front of string: value.replace(/^The /,"")
  • Remove trailing period, “.” at end of string: value.replace(/\.$/,"") (note the “.” needs to be escaped with \ since it has a meaning in regex)
• Classes of characters
  • Remove all punctuation marks: value.replace(/\p{Punct}/,' ')
  • Remove all letters: value.replace(/\p{IsAlphabetic}/,"")