Match

PowerScript function

Description

Determines whether a string’s value contains a particular pattern of
characters.

Syntax

Match ( string, textpattern )

1	Match ( string, textpattern )

Argument	Description
string	The string in which you want to look for a pattern of characters
textpattern	A string whose value is the text pattern

Return value

Boolean.

Returns true if string matches textpattern and false if it does not.
Match also returns false if either argument has not been assigned a value
or the pattern is invalid. If any argument’s value is null, Match returns
null.

Usage

Match enables you to evaluate whether a string contains a general
pattern of characters. To find out whether a string contains a specific
substring, use the Pos function.

Textpattern is similar to a regular expression. It consists of
metacharacters, which have special meaning, and ordinary characters, which
match themselves. You can specify that the string begin or end with one or
more characters from a set, or that it contain any characters except those
in a set.

A text pattern consists of metacharacters, which have special
meaning in the match string, and nonmetacharacters, which match the
characters themselves.The following tables explain the meaning and use of
these metacharacters.

Metacharacter	Meaning	Example
Caret (^)	Matches the beginning of a string	^C matches C at the beginning of a string.
Dollar sign ($)	Matches the end of a string	s$ matches s at the end of a string.
Period (.)	Matches any character	. . . matches three consecutive characters.
Backslash ()	Removes the following metacharacter’s special characteristics so that it matches itself	$ matches $.
Character class (a group of characters enclosed in square brackets ([ ]))	Matches any of the enclosed characters	[AEIOU] matches A, E, I, O, or U. You can use hyphens to abbreviate ranges of characters in a character class. For example, [A-Za-z] matches any letter.
Complemented character class (first character inside the brackets is a caret)	Matches any character not in the group following the caret	[^0-9] matches any character except a digit, and [^A-Za-z] matches any character except a letter.

The metacharacters asterisk (*), plus (+), and question mark (?) are
unary operators that are used to specify repetitions in a regular
expression:

Metacharacter	Meaning	Example
* (asterisk)	Indicates zero or more occurrences	A* matches zero or more As (no As, A, AA, AAA, and so on)
+ (plus)	Indicates one or more occurrences	A+ matches one A or more than one A (A, AAA, and so on)
? (question mark)	Indicates zero or one occurrence	A? matches an empty string (“”) or A

Sample patterns

The following table shows various text patterns and sample text that
matches each pattern:

This pattern	Matches
AB	Any string that contains AB; for example, ABA, DEABC, graphAB_one
B*	Any string that contains 0 or more Bs; for example, AC, B, BB, BBB, ABBBC, and so on
AB*C	Any string containing the pattern AC or ABC or ABBC, and so on (0 or more Bs)
AB+C	Any string containing the pattern ABC or ABBC or ABBBC, and so on (1 or more Bs)
ABB*C	Any string containing the pattern ABC or ABBC or ABBBC, and so on (1 B plus 0 or more Bs)
^AB	Any string starting with AB
AB?C	Any string containing the pattern AC or ABC (0 or 1 B)
^[ABC]	Any string starting with A, B, or C
[^ABC]	A string containing any characters other than A, B, or C
^[^abc]	A string that begins with any character except a, b, or c
^[^a-z]$	Any single-character string that is not a lowercase letter (^ and $ indicate the beginning and end of the string)
[A-Z]+	Any string with one or more uppercase letters
^[0-9]+$	Any string consisting only of digits
^[0-9][0-9][0-9]$	Any string consisting of exactly three digits
^([0-9][0-9][0-9])$	Any consisting of exactly three digits enclosed in parentheses

Examples

This statement returns true if the text in sle_ID begins with one or
more uppercase or lowercase letters (^ at the beginning of the pattern
means that the beginning of the string must match the characters that
follow):

Match(sle_ID.Text, "^[A-Za-z]")

1	Match(sle_ID.Text, "^[A-Za-z]")

This statement returns false if the text in sle_ID contains any
digits (^ inside a bracket is a complement operator):

Match(sle_ID.Text, "[^0-9]")

1	Match(sle_ID.Text, "[^0-9]")

This statement returns true if the text in sle_ID contains one
uppercase letter:

Match(sle_ID.Text, "[A-Z]")

1	Match(sle_ID.Text, "[A-Z]")

This statement returns true if the text in sle_ID contains one or
more uppercase letters (+ indicates one or more occurrences of the
pattern):

Match(sle_ID.Text, "[A-Z]+")

1	Match(sle_ID.Text, "[A-Z]+")

This statement returns false if the text in sle_ID contains anything
other than two digits followed by a letter (^ and $ indicate the beginning
and end of the string):

Match(sle_ID.Text, "^[0-9][0-9][A-Za-z]$")

1	Match(sle_ID.Text, "^[0-9][0-9][A-Za-z]$")

See also

Pos

Match method for DataWindows in the section called “Match” in DataWindow Reference.

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Powerbuilder Documentation 2017

August 20, 2023

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