IF-THEN-ELSE-END IF Statement.

IF..THEN…ELSE…END IF Statement:

• IF…THEN…ELSE statement enable us to specify two different groups of statements for execution.
• One group is evaluated when the condition evaluates to “FALSE”.

Syntax:
    IF condition THEN
        Sequences of statements;
    ELSE
        Sequences of statements;
    END IF;


Example-1:
SQL>DECLARE
        Firstnum NUMBER:=&Fnum;
        Secondnum NUMBER:=&Snum;
    BEGIN
    IF Firstnum<Secondnum THEN
    DBMS_OUTPUT.PUT_LINE('Smallest of two number is'||Firstnum);
    ELSE
    DBMS_OUTPUT.PUT_LINE('Smallest of two number is'||Secondnum);
    END IF;
    END;

Example-2:
SQL>DECLARE
        Num NUMBER:=&Enternumber;
    BEGIN
    IF MOD(Num,2)=0 THEN
    DBMS_OUTPUT.PUT_LINE(Num||' is an Even Number.');
    ELSE
    DBMS_OUTPUT.PUT_LINE(Num||'is an Odd Number.');
    END IF;
    END;

Example-3:
SQL>DECLARE
    Number1 NUMBER:=& Number1;
    Number2 NUMBER:=& Number2;
    BEGIN
    IF Number1>Number2 THEN
    DBMS_OUTPUT.PUT_LINE('The Greatest Number is:'||Number1);
    ELSE
        IF Number2>Number1 THEN
        DBMS_OUTPUT.PUT_LINE('The Greatest Number is:'||Number2);
            ELSE
            DBMS_OUTPUT.PUT_LINE('The Number are equal'||Number1||'and'||Number2);
            END IF;
        END IF;
    END;