lineBoundary - Match start or end of line - MATLAB (original) (raw)
Main Content
Match start or end of line
Since R2020b
Syntax
Description
[pat](#mw%5Fce65e61d-2185-4623-9074-5f0a2455fc85%5Fsep%5Fmw%5F5d8462f7-c5cb-4493-9ed2-15c426e9be6f) = lineBoundary creates a pattern that matches the start or end of a line, including newline characters.lineBoundary can be negated using the ~ operator. When negated, ~lineBoundary matches between any two characters so long as neither is a newline character.
[pat](#mw%5Fce65e61d-2185-4623-9074-5f0a2455fc85%5Fsep%5Fmw%5F5d8462f7-c5cb-4493-9ed2-15c426e9be6f) = lineBoundary([type](#mw%5Fce65e61d-2185-4623-9074-5f0a2455fc85%5Fsep%5Fmw%5F3db4ca55-65f2-47cb-817d-7df607c4d0ee)) specifies whether to match at the start or end of a line. type can be'start', 'end', or 'either' (default).
Examples
Match Boundaries of Lines
Use lineBoundary to match the start or end of a line of text.
Create a string with a newline character. Create a pattern that matches letters following the start of a new line.
txt = "This is line one." + newline + "Here is line two."; pat = lineBoundary + lettersPattern;
Extract the pattern.
firstWord = extract(txt,pat)
firstWord = 2x1 string "This" "Here"
Match Start and End Boundaries of Lines
Use the "start" option for lineBoundary to match the specified endpoint of a line.
Create a string with newline characters. Create a pattern that matches any characters between two "start" boundaries of lines.
txt = "This is line one." + newline + "Here is line two." + newline + "Last but not least."; pat = lineBoundary("start") + wildcardPattern(1,inf) + lineBoundary("start");
Extract the pattern.
ans = 2x1 string "This is line one...." "Here is line two...."
Negate Boundaries of Lines
Use the ~ operator to negate lineBoundary. This matches boundaries between two characters when neither is a newline character.
Create a string with a newline character. Create a pattern that matches letters that are neither at the start nor end of a line of text.
txt = "This is line one" + newline + "Here is line two"; pat = ~lineBoundary + lettersPattern + ~lineBoundary;
Extract the pattern.
firstWord = extract(txt,pat)
firstWord = 8x1 string "his" "is" "line" "on" "ere" "is" "line" "tw"
Input Arguments
type — Boundary type
'either' (default) | 'start' | 'end'
Boundary type, specified as 'start', 'end', or 'either'.
Data Types: char | string
Output Arguments
pat — Pattern expression
pattern object
Pattern expression, returned as a pattern object.
Extended Capabilities
Thread-Based Environment
Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.
Version History
Introduced in R2020b