Swap Function

[Nicola]

Hello,
i was seeing and trying some swap functions (value swapping between two variables).
The attached listing gives an example and use.

Code: OxygenBasic

1. 'Swap functions
2. 'hello from Nicola
3. '-----------------
4. use console
5.  
6. sub pprint(string s,a,b)  'serve per stampare i dati
7.  printl "Using " + s +"  "+a + "  "+ b
8. end sub
9.  
10. function swap(int *a, int *b)
11.         local int c=a
12.         a=b :   b=c
13. end function
14.  
15. macro swapp(a,b) 'funziona per qualsiasi tipo di dato
16.  typeof a v=a
17.   a=b : b=v
18. end macro
19.  
20. macro swaps(a,b) 'funziona x qualsiasi dato.
21.  dim as string v(2)={a,b}
22.   a=v(2) : b=v(1)
23. end macro
24.  
25. macro swapar(a,b) 'swap usando il + e il -
26.  a=a+b
27.   b=a-b
28.   a=a-b
29. end macro
30.  
31. macro swaper(a,b) 'swap usando il * e il /
32.  a=a*b
33.   b=a/b
34.   a=a/b
35. end macro
36.  
37. macro swapxor(a,b) 'swap usando il * e il / funziona per soli int
38.  a=a xor b
39.   b=a xor b
40.   a=a xor b
41. end macro
42.  
43.  
44. int a=20, b=35
45. pprint("Before  ",a,b)
46. swap(a,b)
47. pprint("swap    ",a,b)
48. swapar(a,b)
49. pprint("swapar  ",a,b)
50. swaper(a,b)
51. pprint("swaper  ",a,b)
52. swapxor(a,b)
53. pprint("swapxor ",a,b)
54. swaps(a,b)
55. pprint("swaps   ",a,b)
56.  
57. float a=1.5,b=2.5
58. pprint("Before  ",a,b)
59. swapp(a,b)
60. pprint("swapp   ",a,b)
61. swapar(a,b)
62. pprint("swapar  ",a,b)
63. swaper(a,b)
64. pprint("swaper  ",a,b)
65. 'swapxor(a,b)              'non funziona per float
66. 'pprint("swapxor ",a,b)
67. swaps(a,b)
68. pprint("swaps   ",a,b)
69.  
70. string h="Nicola", k="Charles"
71. swapp(h,k)
72. pprint("swapp   ",h,k)
73. swaps(h,k)
74. pprint("swaps   ",h,k)
75.  
76. waitkey
77.  

[Charles Pegge]

Thanks Nicola.

The swap macro will cover most situations efficiently.

Macros often have significant advantages over procedures/functions, supporting multiple types and avoiding the overhead of making calls.