Re: What is going on!?!

*To*: mathgroup at smc.vnet.net*Subject*: [mg104727] Re: [mg104688] What is going on!?!*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Sun, 8 Nov 2009 06:44:49 -0500 (EST)*Reply-to*: hanlonr at cox.net

The output of the For is Null (from documentation on For: "Unless an explicit Return is used, the value returned by For is Null."). When multiplied by x (i.e., 10) gives 10*Null. Put the semi-colon after the right bracket. x = 0; For[i = 1, i <= 10, i++, x = x + 1]; x 10 Bob Hanlon ---- Joe Hays <joehays at vt.edu> wrote: ============= 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