a reverse string (Rosetta Code)

[TempodiBasic]

Hi Guys and Gals of QB64 community

here a demo written for the task of rosetta code http://www.rosettacode.org/wiki/Reverse_a_string

Code: QB64: [Select]

1. 'reverse a string
2. Dim As String A
3.  
4. A = "Hello World!"
5. Print A, Reverse1$(A)
6. A = "This is QB64"
7. Print A, Reverse2$(A)
8. A = "QB64 is Powerful!"
9. Print A, Reverse3$(A)
10. End
11.  
12. Function Reverse1$ (A As String)
13.     Dim ReverseA As String
14.     Dim As Integer Alenght, countFor
15.  
16.     Alenght = Len(A)
17.     For countFor = 1 To Alenght Step 1
18.         ReverseA = ReverseA + Right$(A, 1)
19.         A = Left$(A, Alenght - countFor)
20.     Next countFor
21.     Reverse1$ = ReverseA
22. End Function
23.  
24. Function Reverse2$ (A As String)
25.     Dim ReverseA As String, B As String
26.     Dim As Integer Alenght, countFor
27.     Alenght = Len(A)
28.     B = A
29.     For countFor = 1 To Alenght Step 1
30.         B = Right$(A, countFor)
31.         ReverseA = ReverseA + Left$(B, 1)
32.     Next countFor
33.     Reverse2$ = ReverseA
34. End Function
35.  
36. Function Reverse3$ (A As String)
37.     Dim ReverseA As String
38.     Dim As Integer Alenght, countFor
39.  
40.     Alenght = Len(A)
41.     For countFor = Alenght To 1 Step -1
42.         ReverseA = ReverseA + Mid$(A, countFor, 1)
43.     Next countFor
44.     Reverse3$ = ReverseA
45. End Function
46.  

Please run to test o post a benchmark so we can publish this on website.

[bplus]

Code: QB64: [Select]

1. s$ = "reverse"
2. For i = Len(s$) To 1 Step -1
3.     Print Mid$(s$, i, 1);
4. Next
5.  

[bplus]

Code: QB64: [Select]

1. r$ = "Here is a cool one!" ' b+ Recursive reverse trans QB64 2021-04-11
2. Print reverse$(r$)
3. Function reverse$ (s As String)
4.     If Len(s) = 1 Then reverse$ = s Else revs$ = reverse$(Mid$(s, 2)) + Left$(s, 1)
5. End Function
6.  

[bplus]

Code: QB64: [Select]

1. r$ = "Here is another one without concatenation." ' b+ reverse 2021-04-11
2. Print reverse$(r$)
3. Function reverse$ (s As String)
4.     reverse$ = Space$(Len(s))
5.     For i = Len(s) To 1 Step -1
6.         Mid$(reverse$, Len(s) + 1 - i, 1) = Mid$(s, i, 1)
7.     Next
8. End Function
9.  

[TempodiBasic]

Hi Bplus
I find cool the shortest reverse task!
I think that it is good to show different ways to get the task using different keywords, so MID$ together RIGHT$ and LEFT$ can be a good team.

[bplus]

Hi Bplus
I find cool the shortest reverse task!
I think that it is good to show different ways to get the task using different keywords, so MID$ together RIGHT$ and LEFT$ can be a good team.

Yes! :)

Code: QB64: [Select]

1. r$ = "reverse"
2. Print r$
3. reverse r$
4. Sub reverse (r$)
5.     For i = Len(r$) To 1 Step -1
6.         Locate 2, Len(r$) - i + 1: Print Chr$(Screen(1, i))
7.     Next
8. End Sub
9.  

[bplus]

Oh this is better:

Code: QB64: [Select]

1. r$ = "This is better."
2. Print r$
3. reverse r$
4. Sub reverse (r$)
5.     For i = Len(r$) To 1 Step -1
6.         Locate 1, Len(r$) + 1 + Len(r$) - i + 1: Print Chr$(Screen(1, i))
7.     Next
8. End Sub

[bplus]

Here is a fun one!

Code: QB64: [Select]

1. _Title "Please enter a string to reverse..."
2. While _KeyDown(27) = 0 And _KeyDown(13) = 0
3.     k$ = InKey$
4.     If Len(k$) Then
5.         If Asc(k$) = 8 Then temp$ = Mid$(temp$, 2) Else temp$ = k$ + temp$
6.         Cls
7.         Print temp$
8.     End If
9.     _Limit 10
10. Wend
11.  

[bplus]

This one is fun to watch!

Code: QB64: [Select]

1. r$ = "0123456789"
2. reverse r$
3. Sub reverse (r$)
4.     Print r$
5.     k = 2
6.     While k <= Len(r$)
7.         For i = Len(r$) To k Step -1
8.             t$ = Mid$(r$, i, 1)
9.             Mid$(r$, i, 1) = Mid$(r$, i - 1, 1)
10.             Mid$(r$, i - 1, 1) = t$
11.             Locate 2, 1: Print r$
12.             _Limit 1
13.         Next
14.         k = k + 1
15.     Wend
16. End Sub
17.  

[euklides]

a$ = "reverse": b$ = "": FOR x = 1 TO LEN(a$): b$ = MID$(a$, x, 1) + b$: NEXT x: PRINT b$: SLEEP 

[SpriggsySpriggs]

Here is my version of this challenge, using @TempodiBasic 's suggestion of functions and subs having the same name:

Code: QB64: [Select]

1. Option _Explicit
2.  
3. Dim As String test
4.  
5. test = "This is a test!"
6.  
7. Print Reverse(test)
8. Print test
9. Reverse test
10. Print test
11.  
12. Function Reverse$ (rev As String)
13.     Dim As String s: s = rev
14.     Dim As String * 1 sArr(0 To Len(s))
15.     Dim As _Unsigned Long i
16.     Dim As _Unsigned Long n
17.     n = Len(s) + 1
18.     For i = LBound(sArr) To UBound(sArr)
19.         sArr(i) = Mid$(s, i, 1)
20.     Next
21.     For i = 0 To (n / 2) - 1
22.         Swap sArr(i), sArr(n - i - 1)
23.     Next
24.     s = ""
25.     For i = LBound(sArr) To UBound(sArr) - 1
26.         s = s + sArr(i)
27.     Next
28.     Reverse = s
29. End Function
30.  
31. Sub Reverse (s As String)
32.     Dim As String * 1 sArr(0 To Len(s))
33.     Dim As _Unsigned Long i
34.     Dim As _Unsigned Long n
35.     n = Len(s) + 1
36.     For i = LBound(sArr) To UBound(sArr)
37.         sArr(i) = Mid$(s, i, 1)
38.     Next
39.     For i = 0 To (n / 2) - 1
40.         Swap sArr(i), sArr(n - i - 1)
41.     Next
42.     s = ""
43.     For i = LBound(sArr) To UBound(sArr) - 1
44.         s = s + sArr(i)
45.     Next
46. End Sub

 

[bplus]

Oh here is my best yet!

Code: QB64: [Select]

1. _Title "Reverse Everything!" 'b+ 2021-04-13
2.  
3. Screen _NewImage(216, 64, 32)
4. _Delay .25 'need time for screen to load before attempting to move it.
5. _ScreenMove _Middle
6.  
7. Locate 2, 11: Print "reverse"
8. _PutImage (0, 32), 0, 0, (214, 16)-Step(-216, 16)
9. Sleep
10.  

 

Edit: seemed a pixel off in first screen shot, so I moved over.

[SpriggsySpriggs]

And another version. I know, not really QB64.

Code: C++: [Select]

1. //save this as reverse.h
2. #include <bits/stdc++.h>
3. const char* ReverseString(const char* str){
4.         std::string str2 = str;
5.         reverse(str2.begin(),str2.end());
6.         return str2.c_str();
7. }

Code: QB64: [Select]

1. Option _Explicit
2.  
3. Declare CustomType Library "reverse"
4.     Function Reverse$ Alias "ReverseString" (str As String)
5. End Declare
6.  
7. Print Reverse("This is a test")

[TempodiBasic]

Hey boys
the challange on new ways to do a reverse string is being interesting!

[bplus]

And another one!

Code: QB64: [Select]

1. _Title "Swinging Reverse" 'b+ 2021-04-13
2.  
3. Screen _NewImage(216, 64, 32)
4. _Delay .25 'need time for screen to load before attempting to move it.
5. _ScreenMove _Middle
6. xc = _Width / 2: yc = _Height / 2
7. r& = _NewImage(_Width, _Height, 32)
8. _PrintString (xc - 7 * 4, yc - 8), "reverse"
9. _PutImage , 0, r&
10. xs = 4: dx = -.1
11. Do
12.     Cls
13.     RotoZoom3 xc, yc, r&, xs, 4, 0
14.     xs = xs + dx
15.     If xs < -4 Then xs = -4: dx = -dx
16.     If xs > 4 Then xs = 4: dx = -dx
17.     _Display
18.     _Limit 30
19. Loop
20.  
21. Sub RotoZoom3 (X As Long, Y As Long, Image As Long, xScale As Single, yScale As Single, radianRotation As Single) ' 0 at end means no scaling of x or y
22.     Dim px(3) As Single: Dim py(3) As Single
23.     Dim W&, H&, sinr!, cosr!, i&, x2&, y2&
24.     W& = _Width(Image&): H& = _Height(Image&)
25.     px(0) = -W& / 2: py(0) = -H& / 2: px(1) = -W& / 2: py(1) = H& / 2
26.     px(2) = W& / 2: py(2) = H& / 2: px(3) = W& / 2: py(3) = -H& / 2
27.     sinr! = Sin(-radianRotation): cosr! = Cos(-radianRotation)
28.     For i& = 0 To 3
29.         x2& = xScale * (px(i&) * cosr! + sinr! * py(i&)) + X: y2& = yScale * (py(i&) * cosr! - px(i&) * sinr!) + Y
30.         px(i&) = x2&: py(i&) = y2&
31.     Next
32.     _MapTriangle _Seamless(0, 0)-(0, H& - 1)-(W& - 1, H& - 1), Image To(px(0), py(0))-(px(1), py(1))-(px(2), py(2))
33.     _MapTriangle _Seamless(0, 0)-(W& - 1, 0)-(W& - 1, H& - 1), Image To(px(0), py(0))-(px(3), py(3))-(px(2), py(2))
34. End Sub
35.  
36.