/usr/share/doc/octave/octave.html/Comparing-Strings.html

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Comparing Strings (GNU Octave)</title>

<meta name="description" content="Comparing Strings (GNU Octave)">
<meta name="keywords" content="Comparing Strings (GNU Octave)">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<link href="index.html#Top" rel="start" title="Top">
<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Strings.html#Strings" rel="up" title="Strings">
<link href="Manipulating-Strings.html#Manipulating-Strings" rel="next" title="Manipulating Strings">
<link href="Converting-Numerical-Data-to-Strings.html#Converting-Numerical-Data-to-Strings" rel="prev" title="Converting Numerical Data to Strings">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.indentedblock {margin-right: 0em}
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smalllisp {margin-left: 3.2em}
kbd {font-style: oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nolinebreak {white-space: nowrap}
span.roman {font-family: initial; font-weight: normal}
span.sansserif {font-family: sans-serif; font-weight: normal}
ul.no-bullet {list-style: none}
-->
</style>
<link rel="stylesheet" type="text/css" href="octave.css">


</head>

<body lang="en">
<a name="Comparing-Strings"></a>
<div class="header">
<p>
Next: <a href="Manipulating-Strings.html#Manipulating-Strings" accesskey="n" rel="next">Manipulating Strings</a>, Previous: <a href="Creating-Strings.html#Creating-Strings" accesskey="p" rel="prev">Creating Strings</a>, Up: <a href="Strings.html#Strings" accesskey="u" rel="up">Strings</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Comparing-Strings-1"></a>
<h3 class="section">5.4 Comparing Strings</h3>

<p>Since a string is a character array, comparisons between strings work
element by element as the following example shows:
</p>
<div class="example">
<pre class="example">GNU = &quot;GNU's Not UNIX&quot;;
spaces = (GNU == &quot; &quot;)
     &rArr; spaces =
       0   0   0   0   0   1   0   0   0   1   0   0   0   0
</pre></div>

<p>To determine if two strings are identical it is necessary to use the
<code>strcmp</code> function.  It compares complete strings and is case
sensitive.  <code>strncmp</code> compares only the first <code>N</code> characters (with
<code>N</code> given as a parameter).  <code>strcmpi</code> and <code>strncmpi</code> are the
corresponding functions for case-insensitive comparison.
</p>
<a name="XREFstrcmp"></a><dl>
<dt><a name="index-strcmp"></a>: <em></em> <strong>strcmp</strong> <em>(<var>s1</var>, <var>s2</var>)</em></dt>
<dd><p>Return 1 if the character strings <var>s1</var> and <var>s2</var> are the same,
and 0 otherwise.
</p>
<p>If either <var>s1</var> or <var>s2</var> 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.
</p>
<p><strong>Caution:</strong> For compatibility with <small>MATLAB</small>, Octave&rsquo;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.
</p>
<p><strong>See also:</strong> <a href="#XREFstrcmpi">strcmpi</a>, <a href="#XREFstrncmp">strncmp</a>, <a href="#XREFstrncmpi">strncmpi</a>.
</p></dd></dl>


<a name="XREFstrncmp"></a><dl>
<dt><a name="index-strncmp"></a>: <em></em> <strong>strncmp</strong> <em>(<var>s1</var>, <var>s2</var>, <var>n</var>)</em></dt>
<dd><p>Return 1 if the first <var>n</var> characters of strings <var>s1</var> and <var>s2</var>
are the same, and 0 otherwise.
</p>
<div class="example">
<pre class="example">strncmp (&quot;abce&quot;, &quot;abcd&quot;, 3)
      &rArr; 1
</pre></div>

<p>If either <var>s1</var> or <var>s2</var> 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.
</p>
<div class="example">
<pre class="example">strncmp (&quot;abce&quot;, {&quot;abcd&quot;, &quot;bca&quot;, &quot;abc&quot;}, 3)
     &rArr; [1, 0, 1]
</pre></div>

<p><strong>Caution:</strong> For compatibility with <small>MATLAB</small>, Octave&rsquo;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.
</p>
<p><strong>See also:</strong> <a href="#XREFstrncmpi">strncmpi</a>, <a href="#XREFstrcmp">strcmp</a>, <a href="#XREFstrcmpi">strcmpi</a>.
</p></dd></dl>


<a name="XREFstrcmpi"></a><dl>
<dt><a name="index-strcmpi"></a>: <em></em> <strong>strcmpi</strong> <em>(<var>s1</var>, <var>s2</var>)</em></dt>
<dd><p>Return 1 if the character strings <var>s1</var> and <var>s2</var> are the same,
disregarding case of alphabetic characters, and 0 otherwise.
</p>
<p>If either <var>s1</var> or <var>s2</var> 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.
</p>
<p><strong>Caution:</strong> For compatibility with <small>MATLAB</small>, Octave&rsquo;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.
</p>
<p><strong>Caution:</strong> National alphabets are not supported.
</p>
<p><strong>See also:</strong> <a href="#XREFstrcmp">strcmp</a>, <a href="#XREFstrncmp">strncmp</a>, <a href="#XREFstrncmpi">strncmpi</a>.
</p></dd></dl>


<a name="XREFstrncmpi"></a><dl>
<dt><a name="index-strncmpi"></a>: <em></em> <strong>strncmpi</strong> <em>(<var>s1</var>, <var>s2</var>, <var>n</var>)</em></dt>
<dd><p>Return 1 if the first <var>n</var> character of <var>s1</var> and <var>s2</var> are the
same, disregarding case of alphabetic characters, and 0 otherwise.
</p>
<p>If either <var>s1</var> or <var>s2</var> 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.
</p>
<p><strong>Caution:</strong> For compatibility with <small>MATLAB</small>, Octave&rsquo;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.
</p>
<p><strong>Caution:</strong> National alphabets are not supported.
</p>
<p><strong>See also:</strong> <a href="#XREFstrncmp">strncmp</a>, <a href="#XREFstrcmp">strcmp</a>, <a href="#XREFstrcmpi">strcmpi</a>.
</p></dd></dl>


<hr>
<div class="header">
<p>
Next: <a href="Manipulating-Strings.html#Manipulating-Strings" accesskey="n" rel="next">Manipulating Strings</a>, Previous: <a href="Creating-Strings.html#Creating-Strings" accesskey="p" rel="prev">Creating Strings</a>, Up: <a href="Strings.html#Strings" accesskey="u" rel="up">Strings</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
</div>



</body>
</html>
octave-doc 4.2.2-1ubuntu1 / usr / share / doc / octave / octave.html / Comparing-Strings.html
