[julia-users] Re: function! vs. function

[digxx]

Thx evan.
just to clarify: when calling:
function f(a,farr)
for i=1:n
for j=1:n
farr[j,i] = (a[j,:]*a[:,i] - A[j,:]*a[:,i])[1] - k2[j,i]
end
end
end

f(x) with my previously defined x I get an error

while calling

function f!(a,farr)
for i=1:n
for j=1:n
farr[j,i] = (a[j,:]*a[:,i] - A[j,:]*a[:,i])[1] - k2[j,i]
end
end
end

f!(x) I get some result which is nonsense (in this case x^2)
but it doesnt show up an error...

I know the original purpose is to specify farr as second argument to fill 
it. That both works