MATLAB Function Reference    
regexp

Match regular expression

Syntax

Description

start = regexp(str,expr) returns a row vector, start, containing the indices of the substrings in str that match the regular expression string, expr.

When either str or expr is a cell array of strings, regexp returns an m-by-n cell array of row vectors of indices, where m is the the number of strings in str and n is the number of regular expression patterns in expr.

[start,finish] = regexp(str,expr) returns an additional row vector finish, that contains the indices of the last character of the corresponding substrings in start.

[start,finish,tokens] = regexp(str,expr) returns a 1-by-n cell array, tokens, of beginining and ending indices of tokens within the corresponding substrings in start and finish. Tokens are denoted by parentheses in the expression, expr.

[...] = regexp(str,expr,'once') finds just the first match. (By default, regexp returns all matches.) If no matches are found, then all return values are empty.

Remarks

See Regular Expressions, in the MATLAB documentation, for a listing of all regular expression metacharacters supported by MATLAB.

regexp does not support international character sets.

Examples

Example 1

Return a row vector of indices that match words that start with c, end with t, and contain one or more vowels between them:

Example 2

Return a cell array of row vectors of indices that match capital letters and whitespaces in the cell array of strings, str:

Capital letters, '[A-Z]', were found at these str indices:

Space characters, '\s', were found at these str indices:

Example 3

Return the starting and ending indices of words containing the letter x:

Example 4

Return the starting and ending indices of substrings contained by the letter s. Also return the starting and ending indices of the token defined within the parentheses:

See Also

regexpi, regexprep, strfind, findstr, strmatch, strcmp, strcmpi, strncmp, strncmpi


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