Re: Instructions in for
- To: mathgroup at smc.vnet.net
- Subject: [mg89392] Re: Instructions in for
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Sun, 8 Jun 2008 02:31:54 -0400 (EDT)
- Organization: The Open University, Milton Keynes, UK
- References: <g2dboa$9pm$1@smc.vnet.net>
Alejandra Lozada wrote:
> Hello Group,
>
> ______________________________________________
> QUESTION: how to introduce many instructions in for?
> ______________________________________________
>
>
> In C++ it is possible to use while/for and
> include many instructions:
>
> for( i=0; i<n; i++ ){
> instructions,
> as many as you
> like }
>
> In Mathematica, one instruction (Print) :
>
> For[ i=1, i<n, i++, Print[i] ]
> how can I include more instructions?
What you are looking for is how to build compound expression. To do so,
use the *CompoundExpression[]* built-in function or its shortcut ; (the
semicolumn). For example,
For[t = 1; k = 1, k <= 5, k++, t *= k; Print[t];
If[k < 2, Continue[]];
t += 2]
Note that, as in C++, we can also have multiple initializations, tests,
and incrementation in one for-loop header. In the example above, both t
and k are initialized at the beginning of the loop. The built-in
functions *Continue[]* and *Break[]* should do what you expect from a
C++ background.
See
http://reference.wolfram.com/mathematica/ref/CompoundExpression.html
Regards,
-- Jean-Marc