this operator is used to increase or decrease the value of variable to 1.
a++ --> increment the value of a by 1.
--b --> decrement the value of b by 1.
Prefix:
In prefix, the value of variable is incremented or decremented first, then it is used.
Assume a = 20 then b = ++a, the value of a is 21 and b also 21. First the value of a is incremented by 1 and then new value is stored in b.
postfix:
In postfix, the value of variable is used first then the value or variable is incremented or decremented.
Assume a=20 then b=a++, the value if a is 21 but b is 20. First the value of a is stored in b, then the value of a is incremented by 1.
