Variables

There are only 26 possible variables in CJam: single uppercase letters A to Z. All variables are global. At the start of the program, variables are initialized like this:

A=10
B=11
C=12
D=13
E=14
F=15
G=16
H=17
I=18
J=19
K=20
L="" (same as [])
M=""
N=newline string
O=""
P=pi (3.141592653589793)
Q=""
R=""
S=" " (space)
T=0
U=0
V=0
W=-1
X=1
Y=2
Z=3

The variables can get any values during the course of the program.