Expressions are constructed by using operands and operators.
An operand is a variable, constant, literal, or function call that contributes a value to an expression.
An operator like + or -indicates what the program should do with the operands.
An example of a simple expression is shown in the following code.
SQL> SQL>-- w ww . j av a 2 s . c om SQL> declare 2 v_i1_nr NUMBER; 3 v_i2_nr NUMBER; 4 begin 5 --Represents an example of a binary 6 --operator / which requires two operands. 7 v_i1_nr:=10/3; 8 9 10 11 v_i2_nr:=-vi1_nr; 12 end; 13 / SQL>