Expressions in java

An expression is a valid combination of operators and operands.
In general there are two kind of expressions.
Constant expression and variable expression

• Constant expression:- Operands are either literals or constants. These are evaluated at compile time.

e.g. 3+2, 9*8

• Variable expression:- If any operand is variable than it is  variable expression. These are evaluated at run time.

e.g. a+b, b/c