Re: What is going on!?!
- To: mathgroup at smc.vnet.net
 - Subject: [mg104734] Re: [mg104688] What is going on!?!
 - From: "David Park" <djmpark at comcast.net>
 - Date: Sun, 8 Nov 2009 06:46:57 -0500 (EST)
 - References: <23886295.1257594705714.JavaMail.root@n11>
 
I think it is generally a good technique to put multiple statements in one
cell, but you need to insert a line return (Enter) before the last x. That
is, the last x should be on a separate line - but in the same cell.
Because of the last ";" the For statement returned a Null, which would
normally suppress output from a line, but you multiplied it by x and that's
why you got 10 Null.
Generally, in Mathematica, it is better to use Procedural programming
statements. Something similar could be done with:
x = 0;
Do[x++, {10}]
X
x = 0; numbers = {x};
While[x < 10, x = x + 1; numbers = Join[numbers, {x}]]
numbers
David Park
djmpark at comcast.net
http://home.comcast.net/~djmpark/  
From: Joe Hays [mailto:joehays at vt.edu] 
Can anyone tell me why the output is not a simple "10" instead of "10 Null"?
In[3]:= x = 0;
For[i = 1, i <= 10, i++,
  x = x + 1;
  ] x
Out[4]= 10 Null