Pangram checker

BBC BASIC

<lang bbcbasic> FOR test% = 1 TO 2

       READ test$
       PRINT """" test$ """ " ;
       IF FNpangram(test$) THEN
         PRINT "is a pangram"
       ELSE
         PRINT "is not a pangram"
       ENDIF
     NEXT test%
     END
     
     DATA "The quick brown fox jumped over the lazy dog"
     DATA "The five boxing wizards jump quickly"
     
     DEF FNpangram(A$)
     LOCAL C%
     A$ = FNlower(A$)
     FOR C% = ASC("a") TO ASC("z")
       IF INSTR(A$, CHR$(C%)) = 0 THEN = FALSE
     NEXT
     = TRUE
     
     DEF FNlower(A$)
     LOCAL A%, C%
     FOR A% = 1 TO LEN(A$)
       C% = ASCMID$(A$,A%)
       IF C% >= 65 IF C% <= 90 MID$(A$,A%,1) = CHR$(C%+32)
     NEXT
     = A$</lang>

Output:

"The quick brown fox jumped over the lazy dog" is not a pangram
"The five boxing wizards jump quickly" is a pangram

String manipulation is expensive, especially in loops, so it may be better to buffer the string and use character values:

DEFFNisPangram(text$)
  LOCAL size%,text%,char%,bits%
  size%=LENtext$
  IF size%<27 THEN =FALSE:REM too few characters
  DIM text% LOCAL size%:REM BB4W and RISC OS 5 only
  $text%=text$:REM buffer the string
  FOR text%=text% TO text%+size%-1:REM each character
    char%=?text% OR 32:REM to lower case
    IF 96<char% AND char%<123 THEN bits%=bits% OR 1<<(char%-97):REM set ordinal bit
    IF bits%=&3FFFFFF THEN =TRUE:REM all ordinal bits set
  NEXT text%
=FALSE