Task

Test whether an integer is even or odd.

There is more than one way to solve this task:

 Use the even and odd predicates, if the language provides them.
 Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
 Divide i by 2. The remainder equals 0 iff i is even. The remainder equals +1 or -1 iff i is odd.
 Use modular congruences:
 i ≡ 0 (mod 2) iff i is even.
 i ≡ 1 (mod 2) iff i is odd.


 
rem - return true (-1) if even, otherwise false (0)
function even(i = integer) = integer
var one = integer    rem - both operands must be variables 
one = 1
end = ((i and one) = 0)
 
rem - exercise the function
var i = integer
for i = 1 to 10 step 3
   print i; " is ";
   if even(i) then
     print "even"
   else
     print "odd"
next
 
end