Characters and Strings - MATLAB & Simulink (original) (raw)

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Text in character arrays and string arrays

Character arrays and string arrays provide storage for text data in MATLAB®.

A character array is a sequence of characters, just as a numeric array is a sequence of numbers. A typical use is to store short pieces of text as character vectors, such as c = 'Hello World'.
A string array is a container for pieces of text. String arrays provide a set of functions for working with text as data. You can create strings using double quotes, such as str = "Greetings friend". To convert data to string arrays, use the string function.

Functions

string	String array
strings	Create string array with no characters
join	Combine strings
plus	Add numbers, append strings

char	Character array
cellstr	Convert to cell array of character vectors
blanks	Create character array of blanks
newline	Create newline character

compose	Format data into multiple strings
sprintf	Format data into string or character vector
strcat	Concatenate strings horizontally
append	Combine strings

ischar	Determine if input is character array
iscellstr	Determine if input is cell array of character vectors
isstring	Determine if input is string array
isStringScalar	Determine if input is string array with one element

strlength	Lengths of strings
isstrprop	Determine which characters in input strings are of specified category
isletter	Determine which characters are letters
isspace	Determine which characters are space characters

contains	Determine if pattern is in strings
matches	Determine if pattern matches strings
count	Count occurrences of pattern in strings
endsWith	Determine if strings end with pattern
startsWith	Determine if strings start with pattern
strfind	Find strings within other strings
sscanf	Read formatted data from strings

replace	Find and replace one or more substrings
replaceBetween	Replace substrings between start and end points
strrep	Find and replace substrings

pattern	Patterns to search and match text (Since R2020b)

alphanumericBoundary	Match boundary between alphanumeric and non-alphanumeric characters (Since R2020b)
digitBoundary	Match boundary between digit characters and non-digit characters (Since R2020b)
letterBoundary	Match boundary between letter characters and non-letter characters (Since R2020b)
whitespaceBoundary	Match boundary between whitespace characters and non-whitespace characters (Since R2020b)
lineBoundary	Match start or end of line (Since R2020b)
textBoundary	Match start or end of text (Since R2020b)
lookAheadBoundary	Match boundary before specified pattern (Since R2020b)
lookBehindBoundary	Match boundary following specified pattern (Since R2020b)

regexp	Match regular expression (case sensitive)
regexpi	Match regular expression (case insensitive)
regexprep	Replace text using regular expression
regexptranslate	Translate text into regular expression
regexpPattern	Pattern that matches specified regular expression (Since R2020b)

join	Combine strings
plus	Add numbers, append strings
split	Split strings at delimiters
splitlines	Split strings at newline characters
strjoin	Join strings in array
strsplit	Split string or character vector at specified delimiter
strtok	Selected parts of strings
extract	Extract substrings from strings (Since R2020b)
extractAfter	Extract substrings after specified positions
extractBefore	Extract substrings before specified positions
extractBetween	Extract substrings between start and end points

erase	Delete substrings within strings
eraseBetween	Delete substrings between start and end points
extract	Extract substrings from strings (Since R2020b)
extractAfter	Extract substrings after specified positions
extractBefore	Extract substrings before specified positions
extractBetween	Extract substrings between start and end points
insertAfter	Insert strings after specified substrings
insertBefore	Insert strings before specified substrings
pad	Add leading or trailing characters to strings
strip	Remove leading and trailing characters from strings
lower	Convert strings to lowercase
upper	Convert strings to uppercase
reverse	Reverse order of characters in strings
deblank	Remove trailing whitespace from ends of strings
strtrim	Remove leading and trailing whitespace from strings
strjust	Justify strings

matches	Determine if pattern matches strings
strcmp	Compare strings
strcmpi	Compare strings (case insensitive)
strncmp	Compare first n characters of strings (case sensitive)
strncmpi	Compare first n characters of strings (case insensitive)

Text in String and Character Arrays
Store and manipulate text using either string arrays or character arrays.
Analyze Text Data with String Arrays
This example shows how to analyze text data with string arrays. It shows how to store, split, and sort text, and how to compute and collect statistics for text in a string array.
- Compare Text
- Test for Empty Strings and Missing Values
Formatting Text
Compose character arrays or string arrays that include ordinary text and data formatted to your specification.
Search and Replace Text
MATLAB provides several functions to search for, replace, or extract text in string arrays and character vectors.
- Build Pattern Expressions
- Regular Expressions
- Lookahead Assertions in Regular Expressions
- Tokens in Regular Expressions
- Dynamic Regular Expressions
Unicode and ASCII Values
MATLAB stores all characters as Unicode characters. Both strings and character vectors use the same encoding. You can convert characters to their Unicode code values, and numbers to characters.
Hexadecimal and Binary Values
Specify hexadecimal and binary values either as literals or as text. Hexadecimal and binary literals are stored as integers. You can convert text representing hexadecimal and binary values to numbers, and numbers to text representations.