QBASIC Program to print string pattern a, BB, ccc, DDDD, eeeee, FFFFFF

QBAIC String pattern printing program a, BB, ccc, DDDD, eeeee, ffffff. There can be more then one solution or code to print this kind of patterns in qbasic. It will be better to use LCASE$ and UCASE$ library functions with IF .. ELSE Statement. We will put the string 'abcdef' in a string variable s$ and we will go through for loop with MID$ function to read each character. If the loop is even then we will print the latter in capital letter otherwise in small letter. 

Simple Program

CLS
s$ = "abcdef"
FOR i = 1 TO LEN(s$)
    FOR j = 1 TO i
        l$ = MID$(s$, i, 1)
        IF i MOD 2 = 0 THEN
            PRINT UCASE$(l$);
        ELSE
            PRINT LCASE$(l$);
        END IF
    NEXT j
    PRINT
NEXT i
END

OUTPUT

a
BB
ccc
DDDD
eeeee
FFFFFF

Using SUB ... END SUB

DECLARE SUB Pat(s$)
CLS
s$ = "abcdef"
CALL Pat(s$)
END

SUB Pat (s$)
    FOR i = 1 TO LEN(s$)
        FOR j = 1 TO i
            l$ = MID$(s$, i, 1)
            IF i MOD 2 = 0 THEN
                PRINT UCASE$(l$);
            ELSE
                PRINT LCASE$(l$);
            END IF
        NEXT j
        PRINT
    NEXT i
END SUB

Using FUNCTION ... END

DECLARE FUNCTION Pat(s$)
CLS
s$ = "abcdef"
c = Pat(s$)
END

FUNCTION Pat (s$)
    FOR i = 1 TO LEN(s$)
        FOR j = 1 TO i
            l$ = MID$(s$, i, 1)
            IF i MOD 2 = 0 THEN
                PRINT UCASE$(l$);
            ELSE
                PRINT LCASE$(l$);
            END IF
        NEXT j
        PRINT
    NEXT i
END FUNCTION