Array : The array object
++x is pre-increment and --x is pre-decrement
x++ is post-increment and x-- is post-decrement
With ++x and --x: means x is incremented BEFORE being used.
With x++ and x--: means x is incremented AFTER being used.
Examples
number a = 1;
number b;
b = ++a;
print(b); // 2
print(a); // 2
b = --a;
print(b); // 1
print(a); // 1
number c = 3;
number d;
d = c++;
print(d); // 3
print(c); // 4
d = c--;
print(d); // 4
print(c); // 3