Reverse a string: Difference between revisions

==={{header|Applesoft BASIC}}===

<syntaxhighlight lang="applesoftbasic">10 A$ = "THE FIVE BOXING WIZARDS JUMP QUICKLY"

20 GOSUB 100REVERSE

30 PRINT R$

40 END

100 REMREVERSE A$

110 R$ = ""

120 FOR I = 1 TO LEN(A$)

130 R$ = MID$(A$, I, 1) + R$

140 NEXT I

150 RETURN</syntaxhighlight>

==={{header|Commodore BASIC}}===

{{works with|Commodore BASIC|3.5,7.0}}

Commodore BASIC 3.5 turned MID$ into an lvalue function, and assigning a string of the same length to MID$ replaces the characters instead of allocating a new string, so the reversal can be done in-place:

<syntaxhighlight lang="basic">

100 INPUT "STRING";S$

110 FOR I=1 TO INT(LEN(S$)/2)

120 : J=LEN(S$)+1-I

130 : T$=MID$(S$,I,1)

140 : MID$(S$,I,1) = MID$(S$,J,1)

150 : MID$(S$,J,1) = T$

160 NEXT I

170 PRINT S$</syntaxhighlight>

{{Out}}

<pre>STRING? THIS IS A TEST

TSET A SI SIHT

READY.</pre>

==={{header|QuickBASIC}}===

{{works with|QBasic|1.1}}

{{works with|QuickBasic|4.5}}

<syntaxhighlight lang="qbasic">function reverse$(a$)

b$ = ""

for i = 1 to len(a$)

b$ = mid$(a$, i, 1) + b$

next i

reverse$ = b$

end function</syntaxhighlight>