Regular expression functions

Overview

These functions perform matching using the standard Perl-style regular expression syntax. See the Regular expression reference for links to detailed information on constructing regular expressions.

RegexCount

Returns the number of times that text matches the given regex.

Syntax

RegexCount( text, regex )

The RegexCount function syntax has the following arguments.

Remarks

The function RegexCount counts the matches of regex in text.

Examples

• RegexCount("abc123def456", /\d+/) returns 2.

• RegexCount("abc123def456", /\d/) returns 6.

RegexExtractAll

Finds all substrings where text that matches regex, and returns or replaces them.

Syntax

• RegexExtractAll( text, regex, separator )

• RegexExtractAll( text, regex, separator, replacement )

The RegexExtractAll function syntax has the following arguments.

Remarks

The first form of the function RegexExtractAll finds all substrings where text matches regex, and returns them separated by separator (which may be the empty string "").

The second form of the function RegexExtractAll finds all substrings where text matches regex, replaces them with the replacement string, and returns them separated by separator. References (such as \1) and Perl-style substitution operators are supported in replacement.

Examples

• RegexExtractAll("abc123def456", /\d/, ",") returns 1,2,3,4,5,6.

• RegexExtractAll("abc123def456", /\d+/, ",") returns 123,456.

• RegexExtractAll("abc123", /(\d)/, ",", "n=\1") returns n=1,n=2,n=3.

• RegexExtractAll("abc123def456", /(\d+)/, "|", "n=\1") returns n=123|n=456.

RegexExtractFirst

Finds the first substring where text that matches regex, and returns or replaces it.

Syntax

• RegexExtractFirst( text, regex )

• RegexExtractFirst( text, regex, replacement )

The RegexExtractFirst function syntax has the following arguments.

Remarks

The function RegexExtractFirst finds the first substring where text matches regex, and returns it or (if replacement is specified) replaces it with the replacement string. References (such as \1) and Perl-style substitution operators are supported in replacement.

Examples

• RegexExtractFirst("abc123", /\d/) returns 1.

• RegexExtractFirst("abc123", /\d+/) returns 123.

• RegexExtractFirst("abc123", /(\d+)/, "result=\1") returns result=123.

RegexMatch

Returns a Boolean value, which is True if text matches regex, and False otherwise.

Syntax

RegexMatch( text, regex )

The RegexMatch function syntax has the following arguments.

Remarks

The function RegexMatch tests whether a string matches a given regular expression or not. It returns True if text matches regex. The regex is unanchored unless the ^ and/or $ symbols are used explicitly.

Examples

• RegexMatch("abc123", /\d+/) returns True.

• RegexMatch("abc123", /^\d+/) returns False.

RegexReplaceAll

Replaces all occurrences in text of text matching regex with replacement.

Syntax

RegexReplaceAll( text, pattern, replacement )

The RegexReplaceAll function syntax has the following arguments.

Remarks

The function RegularExprReplaceAll finds all substrings where text matches regex, and replaces them with replacement. References (such as \1) and Perl-style substitution operators are supported in replacement. Replaced text is not re-matched.

Examples

• RegexReplaceAll("abc123", /\d/, "X") returns abcXXX.

• RegexReplaceAll("abc123def", /(\d+)/, /<\1>/) returns abc<123>def.

RegexReplaceFirst

Replaces the first occurrence in text of text matching the given regex with replacement.

Syntax

RegexReplaceFirst( text, regex, replacement )

The RegexReplaceFirst function syntax has the following arguments.

Remarks

The function RegularExprReplaceFirst finds the first substring where text matches regex, and replaces it with replacement. References (such as \1) and Perl-style substitution operators are supported in replacement.

Examples

• RegexReplaceFirst("abc123", /\d/, "X") returns abcX23.

• RegexReplaceFirst("abc123", /\d+/, "X") returns abcX.