letterBoundary - Match boundary between letter characters and non-letter characters - MATLAB (original) (raw)

• Documentation
• Examples
• Functions
• Apps
• Videos
• Answers

Main Content

Match boundary between letter characters and non-letter characters

Since R2020b

Syntax

Description

[pat](#mw%5F7a12db76-c65c-4252-a5b5-f8df65208eef%5Fsep%5Fmw%5F5d8462f7-c5cb-4493-9ed2-15c426e9be6f) = letterBoundary creates a pattern that matches the start or end of a run of letter characters. letterBoundary can be negated using the ~ operator. When negated,~letterBoundary matches the boundary between any two characters except at the start or end of a run of letters.

example

[pat](#mw%5F7a12db76-c65c-4252-a5b5-f8df65208eef%5Fsep%5Fmw%5F5d8462f7-c5cb-4493-9ed2-15c426e9be6f) = letterBoundary([type](#mw%5F7a12db76-c65c-4252-a5b5-f8df65208eef%5Fsep%5Fmw%5F3db4ca55-65f2-47cb-817d-7df607c4d0ee)) specifies whether to match at the start or end of a run of letters and numbers.type can be 'start', 'end', or'either' (default).

example

Examples

collapse all

Use letterBoundary to divide a string along boundaries between letters and nonletter characters.

Create a pattern that matches any letter boundaries.

txt = "123 abc .?! def 456"; pat = letterBoundary;

Use replace to insert "|" characters at the matched boundaries.

ans = "123 |abc| .?! |def| 456"

Use the "start" and "end" options for letterBoundary to match the boundary between letters and nonletter characters.

Create a string that contains several different character types. Create a pattern that matches any characters between a "start" boundary for letters and an "end" boundary.

txt = "123 abc .?! def 456"; pat = letterBoundary("start") + wildcardPattern(1,inf) + letterBoundary("end");

Extract the pattern.

boundaries = extract(txt,pat)

boundaries = 2×1 string "abc" "def"

Use the ~ operator to negate letterBoundary. This matches boundaries between two characters when both are letters or neither are letters.

Create a string that contains several different character types. Create a pattern that matches a negated letterBoundary.

txt = "123 abc .?!"; pat = ~letterBoundary;

Use replace to insert "|" characters to show where ~letterBoundary matches.

boundaries = replace(txt,pat,"|")

boundaries = "|1|2|3| a|b|c |.|?|!|"

Input Arguments

collapse all

Boundary type, specified as 'start', 'end', or 'either'.

Data Types: char | string

Extended Capabilities

Version History

Introduced in R2020b