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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<HTML>
<HEAD>
<TITLE>RETURN Return From Function
</TITLE>
</HEAD>
<BODY>
<H2>RETURN Return From Function
</H2>
<P>
Section: <A HREF=sec_flow.html> Flow Control </A>
<H3>Usage</H3>
The <code>return</code> statement is used to immediately return from
a function, or to return from a <code>keyboard</code> session. The
syntax for its use is
<PRE>
return
</PRE>
<P>
Inside a function, a <code>return</code> statement causes FreeMat
to exit the function immediately. When a <code>keyboard</code> session
is active, the <code>return</code> statement causes execution to
resume where the <code>keyboard</code> session started.
<H3>Example</H3>
In the first example, we define a function that uses a
<code>return</code> to exit the function if a certain test condition
is satisfied.
<P>
<PRE>
return_func.m
function ret = return_func(a,b)
ret = 'a is greater';
if (a > b)
return;
end
ret = 'b is greater';
printf('finishing up...\n');
</PRE>
<P>
Next we exercise the function with a few simple test
cases:
<PRE>
--> return_func(1,3)
finishing up...
ans =
b is greater
--> return_func(5,2)
ans =
a is greater
</PRE>
<P>
In the second example, we take the function and rewrite
it to use a <code>keyboard</code> statement inside the <code>if</code> statement.
<P>
<PRE>
return_func2.m
function ret = return_func2(a,b)
if (a > b)
ret = 'a is greater';
keyboard;
else
ret = 'b is greater';
end
printf('finishing up...\n');
</PRE>
<P>
Now, we call the function with a larger first argument, which
triggers the <code>keyboard</code> session. After verifying a few
values inside the <code>keyboard</code> session, we issue a <code>return</code>
statement to resume execution.
<PRE>
--> return_func2(2,4)
finishing up...
ans =
b is greater
--> return_func2(5,1)
[return_func2,4]--> ret
ans =
a is greater
[return_func2,4]--> a
ans =
5
[return_func2,4]--> b
ans =
1
[return_func2,4]--> return
finishing up...
ans =
a is greater
</PRE>
<P>
</BODY>
</HTML>
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