GNU Octave Manual Version 3by John W. Eaton, David Bateman, Søren Hauberg Paperback (6"x9"), 568 pages ISBN 095461206X RRP £24.95 ($39.95) |

## 5.2 Comparing Strings

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 therefore necessary
to use the `strcmp`

or `strncpm`

functions. Similar
functions exist for doing case-insensitive comparisons.

__Built-in Function:__**strcmp***(*`s1`,`s2`)- Return 1 if the character strings
`s1`and`s2`are the same, and 0 otherwise.If either

`s1`or`s2`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.See also strcmpi, strncmp, strncmpi

__Function File:__**strcmpi***(*`s1`,`s2`)- Ignoring case, return 1 if the character strings
`s1`and`s2`are the same, and 0 otherwise.If either

`s1`or`s2`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 strcmpi function returns 1 if the character strings are equal, and 0 otherwise. This is just the opposite of the corresponding C library function.See also strcmp, strncmp, strncmpi

__Built-in Function:__**strncmp***(*`s1`,`s2`,`n`)- Return 1 if the first
`n`characters of strings`s1`and`s2`are the same, and 0 otherwise.strncmp ("abce", "abcd", 3) => 1

If either

`s1`or`s2`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.See also strncmpi, strcmp, strcmpi

__Function File:__**strncmpi***(*`s1`,`s2`,`n`)- Ignoring case, return 1 if the first
`n`characters of character strings`s1`and`s2`are the same, and 0 otherwise.`s1`or`s2`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.See also strcmp, strcmpi, strncmp

ISBN 095461206X | GNU Octave Manual Version 3 | See the print edition |