Since a string is a character array, comparisons between strings work element by element as the following example shows:

GNU = "GNU's Not UNIX"; spaces = (GNU == " ") ⇒ spaces = 0 0 0 0 0 1 0 0 0 1 0 0 0 0

To determine if two strings are identical it is necessary to use the
`strcmp`

function. It compares complete strings and is case
sensitive. `strncmp`

compares only the first `N`

characters (with
`N`

given as a parameter). `strcmpi`

and `strncmpi`

are the
corresponding functions for case-insensitive comparison.

- :
`tf`=**strcmp**`(`

¶`str1`,`str2`) Return 1 if the character strings

`str1`and`str2`are the same, and 0 otherwise.If either

`str1`or`str2`is a cell array of strings, then an array of the same size is returned, containing the values described above for every member of the cell array. The other argument may also be a cell array of strings (of the same size or with only one element), char matrix or character string.**Caution:**For compatibility with MATLAB, Octave’s strcmp function returns 1 if the character strings are equal, and 0 otherwise. This is just the opposite of the corresponding C library function.

- :
`tf`=**strncmp**`(`

¶`str1`,`str2`,`n`) Return 1 if the first

`n`characters of strings`str1`and`str2`are the same, and 0 otherwise.strncmp ("abce", "abcd", 3) ⇒ 1

If either

`str1`or`str2`is a cell array of strings, then an array of the same size is returned, containing the values described above for every member of the cell array. The other argument may also be a cell array of strings (of the same size or with only one element), char matrix or character string.strncmp ("abce", {"abcd", "bca", "abc"}, 3) ⇒ [1, 0, 1]

**Caution:**For compatibility with MATLAB, Octave’s strncmp function returns 1 if the character strings are equal, and 0 otherwise. This is just the opposite of the corresponding C library function.

- :
`tf`=**strcmpi**`(`

¶`str1`,`str2`) Return 1 if the character strings

`str1`and`str2`are the same, disregarding case of alphabetic characters, and 0 otherwise.If either

`str1`or`str2`is a cell array of strings, then an array of the same size is returned, containing the values described above for every member of the cell array. The other argument may also be a cell array of strings (of the same size or with only one element), char matrix or character string.**Caution:**For compatibility with MATLAB, Octave’s strcmp function returns 1 if the character strings are equal, and 0 otherwise. This is just the opposite of the corresponding C library function.**Caution:**National alphabets are not supported.

- :
`tf`=**strncmpi**`(`

¶`str1`,`str2`,`n`) Return 1 if the first

`n`character of`s1`and`s2`are the same, disregarding case of alphabetic characters, and 0 otherwise.`str1`or`str2`is a cell array of strings, then an array of the same size is returned, containing the values described above for every member of the cell array. The other argument may also be a cell array of strings (of the same size or with only one element), char matrix or character string.**Caution:**For compatibility with MATLAB, Octave’s strncmpi function returns 1 if the character strings are equal, and 0 otherwise. This is just the opposite of the corresponding C library function.**Caution:**National alphabets are not supported.

Despite those comparison functions, there are more specialized function to find the index position of a search pattern within a string.

- :
`retval`=**startsWith**`(`

¶`str`,`pattern`) - :
`retval`=**startsWith**`(`

¶`str`,`pattern`, "IgnoreCase",`ignore_case`) Check whether string(s) start with pattern(s).

Return an array of logical values that indicates which string(s) in the input

`str`(a single string or cell array of strings) begin with the input`pattern`(a single string or cell array of strings).If the value of the parameter

`"IgnoreCase"`

is true, then the function will ignore the letter case of`str`and`pattern`. By default, the comparison is case sensitive.Examples:

## one string and one pattern while considering case startsWith ("hello", "he") ⇒ 1

## one string and one pattern while ignoring case startsWith ("hello", "HE", "IgnoreCase", true) ⇒ 1

## multiple strings and multiple patterns while considering case startsWith ({"lab work.pptx", "data.txt", "foundations.ppt"}, {"lab", "data"}) ⇒ 1 1 0

## multiple strings and one pattern while considering case startsWith ({"DATASHEET.ods", "data.txt", "foundations.ppt"}, "data", "IgnoreCase", false) ⇒ 0 1 0

## multiple strings and one pattern while ignoring case startsWith ({"DATASHEET.ods", "data.txt", "foundations.ppt"}, "data", "IgnoreCase", true) ⇒ 1 1 0

- :
`retval`=**endsWith**`(`

¶`str`,`pattern`) - :
`retval`=**endsWith**`(`

¶`str`,`pattern`, "IgnoreCase",`ignore_case`) Check whether string(s) end with pattern(s).

Return an array of logical values that indicates which string(s) in the input

`str`(a single string or cell array of strings) end with the input`pattern`(a single string or cell array of strings).If the value of the parameter

`"IgnoreCase"`

is true, then the function will ignore the letter case of`str`and`pattern`. By default, the comparison is case sensitive.Examples:

## one string and one pattern while considering case endsWith ("hello", "lo") ⇒ 1

## one string and one pattern while ignoring case endsWith ("hello", "LO", "IgnoreCase", true) ⇒ 1

## multiple strings and multiple patterns while considering case endsWith ({"tests.txt", "mydoc.odt", "myFunc.m", "results.pptx"}, {".docx", ".odt", ".txt"}) ⇒ 1 1 0 0

## multiple strings and one pattern while considering case endsWith ({"TESTS.TXT", "mydoc.odt", "result.txt", "myFunc.m"}, ".txt", "IgnoreCase", false) ⇒ 0 0 1 0

## multiple strings and one pattern while ignoring case endsWith ({"TESTS.TXT", "mydoc.odt", "result.txt", "myFunc.m"}, ".txt", "IgnoreCase", true) ⇒ 1 0 1 0

**See also:**startsWith, regexp, strncmp, strncmpi.

- :
`v`=**findstr**`(`

¶`s`,`t`) - :
`v`=**findstr**`(`

¶`s`,`t`,`overlap`) -
This function is obsolete. Use

`strfind`

instead.Return the vector of all positions in the longer of the two strings

`s`and`t`where an occurrence of the shorter of the two starts.If the optional argument

`overlap`is true (default), the returned vector can include overlapping positions. For example:findstr ("ababab", "a") ⇒ [1, 3, 5]; findstr ("abababa", "aba", 0) ⇒ [1, 5]

**Caution:**`findstr`

is obsolete. Use`strfind`

in all new code.**See also:**strfind, strmatch, strcmp, strncmp, strcmpi, strncmpi, find.

- :
`idx`=**strchr**`(`

¶`str`,`chars`) - :
`idx`=**strchr**`(`

¶`str`,`chars`,`n`) - :
`idx`=**strchr**`(`

¶`str`,`chars`,`n`,`direction`) - :
`[`

`i`,`j`] =**strchr**`(…)`

¶ Search through the string

`str`for occurrences of characters from the set`chars`.The return value(s), as well as the

`n`and`direction`arguments behave identically as in`find`

.This will be faster than using

`regexp`

in most cases.**See also:**find.

- :
`n`=**index**`(`

¶`s`,`t`) - :
`n`=**index**`(`

¶`s`,`t`,`direction`) Return the position of the first occurrence of the string

`t`in the string`s`, or 0 if no occurrence is found.`s`may also be a string array or cell array of strings.For example:

index ("Teststring", "t") ⇒ 4

If

`direction`is`"first"`

, return the first element found. If`direction`is`"last"`

, return the last element found.

- :
`n`=**rindex**`(`

¶`s`,`t`) Return the position of the last occurrence of the character string

`t`in the character string`s`, or 0 if no occurrence is found.`s`may also be a string array or cell array of strings.For example:

rindex ("Teststring", "t") ⇒ 6

The

`rindex`

function is equivalent to`index`

with`direction`set to`"last"`

.

- :
`idx`=**unicode_idx**`(`

¶`str`) Return an array with the indices for each UTF-8 encoded character in

`str`.unicode_idx ("aäbc") ⇒ [1, 2, 2, 3, 4]

- :
`idx`=**strfind**`(`

¶`str`,`pattern`) - :
`idx`=**strfind**`(`

¶`cellstr`,`pattern`) - :
`idx`=**strfind**`(…, "overlaps",`

¶`val`) - :
`idx`=**strfind**`(…, "forcecelloutput",`

¶`val`) Search for

`pattern`in the string`str`and return the starting index of every such occurrence in the vector`idx`.If there is no such occurrence, or if

`pattern`is longer than`str`, or if`pattern`itself is empty, then`idx`is the empty array`[]`

.The optional argument

`"overlaps"`

determines whether the pattern can match at every position in`str`(true), or only for unique occurrences of the complete pattern (false). The default is true.If a cell array of strings

`cellstr`is specified then`idx`is a cell array of vectors, as specified above.The optional argument

`"forcecelloutput"`

forces`idx`to be returned as a cell array of vectors. The default is false.Examples:

strfind ("abababa", "aba") ⇒ [1, 3, 5]

strfind ("abababa", "aba", "overlaps", false) ⇒ [1, 5]

strfind ({"abababa", "bebebe", "ab"}, "aba") ⇒ { [1,1] = 1 3 5 [1,2] = [](1x0) [1,3] = [](1x0) }

strfind ("abababa", "aba", "forcecelloutput", true) ⇒ { [1,1] = 1 3 5 }

- :
`idx`=**strmatch**`(`

¶`s`,`A`) - :
`idx`=**strmatch**`(`

¶`s`,`A`, "exact") -
This function is obsolete.

**Use an alternative**such as`strncmp`

or`strcmp`

instead.Return indices of entries of

`A`which begin with the string`s`.The second argument

`A`must be a string, character matrix, or a cell array of strings.If the third argument

`"exact"`

is not given, then`s`only needs to match`A`up to the length of`s`. Trailing spaces and nulls in`s`and`A`are ignored when matching.For example:

strmatch ("apple", "apple juice") ⇒ 1 strmatch ("apple", ["apple "; "apple juice"; "an apple"]) ⇒ [1; 2] strmatch ("apple", ["apple "; "apple juice"; "an apple"], "exact") ⇒ [1]

**Caution:**`strmatch`

is obsolete (and can produce incorrect results in MATLAB when used with cell arrays of strings. Use`strncmp`

(normal case) or`strcmp`

(`"exact"`

case) in all new code. Other replacement possibilities, depending on application, include`regexp`

or`validatestring`

.**See also:**strncmp, strcmp, regexp, strfind, validatestring.