<html lang="en"> <head> <title>Returning from a Function - GNU Octave</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="GNU Octave"> <meta name="generator" content="makeinfo 4.13"> <link title="Top" rel="start" href="index.html#Top"> <link rel="up" href="Functions-and-Scripts.html#Functions-and-Scripts" title="Functions and Scripts"> <link rel="prev" href="Variable_002dlength-Return-Lists.html#Variable_002dlength-Return-Lists" title="Variable-length Return Lists"> <link rel="next" href="Default-Arguments.html#Default-Arguments" title="Default Arguments"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"><!-- pre.display { font-family:inherit } pre.format { font-family:inherit } pre.smalldisplay { font-family:inherit; font-size:smaller } pre.smallformat { font-family:inherit; font-size:smaller } pre.smallexample { font-size:smaller } pre.smalllisp { font-size:smaller } span.sc { font-variant:small-caps } span.roman { font-family:serif; font-weight:normal; } span.sansserif { font-family:sans-serif; font-weight:normal; } --></style> </head> <body> <div class="node"> <a name="Returning-from-a-Function"></a> <p> Next: <a rel="next" accesskey="n" href="Default-Arguments.html#Default-Arguments">Default Arguments</a>, Previous: <a rel="previous" accesskey="p" href="Variable_002dlength-Return-Lists.html#Variable_002dlength-Return-Lists">Variable-length Return Lists</a>, Up: <a rel="up" accesskey="u" href="Functions-and-Scripts.html#Functions-and-Scripts">Functions and Scripts</a> <hr> </div> <h3 class="section">11.6 Returning from a Function</h3> <p>The body of a user-defined function can contain a <code>return</code> statement. This statement returns control to the rest of the Octave program. It looks like this: <pre class="example"> return </pre> <p>Unlike the <code>return</code> statement in C, Octave's <code>return</code> statement cannot be used to return a value from a function. Instead, you must assign values to the list of return variables that are part of the <code>function</code> statement. The <code>return</code> statement simply makes it easier to exit a function from a deeply nested loop or conditional statement. <p>Here is an example of a function that checks to see if any elements of a vector are nonzero. <pre class="example"> function retval = any_nonzero (v) retval = 0; for i = 1:length (v) if (v (i) != 0) retval = 1; return; endif endfor printf ("no nonzero elements found\n"); endfunction </pre> <p>Note that this function could not have been written using the <code>break</code> statement to exit the loop once a nonzero value is found without adding extra logic to avoid printing the message if the vector does contain a nonzero element. <div class="defun"> — Keyword: <b>return</b><var><a name="index-return-751"></a></var><br> <blockquote><p>When Octave encounters the keyword <code>return</code> inside a function or script, it returns control to the caller immediately. At the top level, the return statement is ignored. A <code>return</code> statement is assumed at the end of every function definition. </p></blockquote></div> </body></html>