characterListPattern

Match characters from list

Since R2020b

Syntax

pat = characterListPattern(characters)

pat = characterListPattern(startCharacter,endCharacter)

Description

pat = characterListPattern(characters) creates a pattern that matches any character included in characters.

pat = characterListPattern(startCharacter,endCharacter) matches any character in the range between startCharacter and endCharacter, including startCharacter and endCharacter.

Examples

Find Vowels in Text

Define a pattern expression, pat, that matches only the lower case vowels a, e, i, o, and u using characterListPattern. Extract the pattern from the string.

txt = "She sells sea shells by the sea shore.";
pat = characterListPattern("aeiou");
vowels = extract(txt,pat)

vowels = 10x1 string
    "e"
    "e"
    "e"
    "a"
    "e"
    "e"
    "e"
    "a"
    "o"
    "e"

Extract Letters from an Alphabetical Range

Use characterListPattern to extract letters falling within a specified alphabetical range.

Define a pattern expression, pat, that matches only the lowercase letters from a to g using characterListPattern. Extract the pattern from the string.

txt = "ABCDEFGHIJKLMONPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
pat = characterListPattern("a","g");
letters1 = extract(txt,pat)

letters1 = 7x1 string
    "a"
    "b"
    "c"
    "d"
    "e"
    "f"
    "g"

Find Words That Start with Vowels

Create pat as a pattern object that matches words beginning with vowels using letterBoundary, characterListPattern, and lettersPattern. Extract the pattern.

txt = "Do you like words like armadillo, echidna, iguana, ostrich, & unicorn?";
pat = letterBoundary + characterListPattern("aeiou") + lettersPattern;
words = extract(txt,pat)

words = 5x1 string
    "armadillo"
    "echidna"
    "iguana"
    "ostrich"
    "unicorn"

Sort Names into Alphabetical Groups

Create names as a string. Use characterListPattern to create a pattern that matches characters A through G. Find names that start with A through G using startsWith. Repeat this process for H through P and Q through Z.

names = ["Andres" "Betty" "Chris" "David" "Etsuko" "Fredrick"...
        "Gaston" "Hasina" "Ian" "Jose" "Karen" "Larry" "Malia"...
        "Nick" "Omar" "Patrick" "Quincy" "Rajesh" "Shruti"...
        "Tau" "Uma" "Veronica" "Wendy" "Xiao"...
        "Yakov" "Zhanna"];
    
NameGroup1 = names(startsWith(names,characterListPattern('A','G')))    

NameGroup1 = 1x7 string
    "Andres"    "Betty"    "Chris"    "David"    "Etsuko"    "Fredrick"    "Gaston"

NameGroup2 = names(startsWith(names,characterListPattern('H','P')))    

NameGroup2 = 1x9 string
    "Hasina"    "Ian"    "Jose"    "Karen"    "Larry"    "Malia"    "Nick"    "Omar"    "Patrick"

NameGroup3 = names(startsWith(names,characterListPattern('Q','Z')))

NameGroup3 = 1x10 string
    "Quincy"    "Rajesh"    "Shruti"    "Tau"    "Uma"    "Veronica"    "Wendy"    "Xiao"    "Yakov"    "Zhanna"

Input Arguments

characters — List of characters to match

character vector | string scalar

List of characters to match, specified as a character vector or string scalar.

Example: pat = characterListPattern("aeiou")

startCharacter — Starting character

character scalar | string scalar containing a single character

Starting character of range of letters to match, specified as a character scalar or a string scalar containing a single character.

Example: pat = characterListPattern("a","d")

endCharacter — Ending character

character scalar | string scalar containing a single character

Ending character of range of letters to match, specified as a character scalar or a string scalar containing a single character.

Example: pat = characterListPattern("C","a")

Output Arguments

pat — Pattern expression

pattern object

Pattern expression, returned as a pattern object.

More About

Character Order for Text

MATLAB^® stores characters as Unicode^® using the UTF-16 character encoding scheme. Character and string arrays are ordered according to the UTF-16 code point order. For the characters that are also the ASCII characters, this order means that uppercase letters come before lowercase letters. Digits and some punctuation also come before letters. For more information on Unicode, including mappings between characters and code values, see Unicode.

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