Function return value

["Jon Perry" <perry@globalnet.co.uk>]

Why does my iscube() function:

iscube(n)=local(f,retVal);f=factor(n)[,2];retVal=true;for (j=1,length(f),if
(f[j]%3!=0,retVal=false));return(retVal)

need to be tested with ==true?

e.g:

for (s=1,100,if (iscube(s)==true,print1(s,",")))

works, but:

for (s=1,100,if (iscube(s),print1(s,",")))

doesn't, unlike the behaviour of inbuilt functions such as issquare().

Jon Perry
perry@globalnet.co.uk
http://www.users.globalnet.co.uk/~perry/maths
BrainBench MVP for HTML and JavaScript
http://www.brainbench.com