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Message |
jruibarroso
Joined: 07 Jan 2006
Posts: 64
Location: Braga
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| how to do a switch with variables |
 Posted: Sun Oct 29, 2006 10:05 am |
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i have this code :
SWITCH (com) {
Case 62 : output_high(L1); // TECLA 3 TV
delay_ms(250);
output_low(L1);
com=0;
break;
Case 61 : output_high(L2); // TECLA 2 TV
delay_ms(250);
output_low(L2);
com=0;
break;
Case 60 : output_high(L3); // TECLA 1 TV
delay_ms(250);
output_low(L3);
com=0;
break;
// Everything is fine ------------------------------------------------------
but i want something like this
SWITCH (variable) {
Case (variable1) : output_high(L1); // TECLA 3 TV
delay_ms(250);
output_low(L1);
com=0;
break;
Case (variable2) : output_high(L2); // TECLA 2 TV
delay_ms(250);
output_low(L2);
com=0;
break;
Case (variable3) : output_high(L3); // TECLA 1 TV
delay_ms(250);
output_low(L3);
com=0;
break;
Any Ideas , please ? |
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Ttelmah
Guest
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| Posted: Sun Oct 29, 2006 2:19 pm |
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"The _switch_ statement, is a multi-way decision, that tests whether an expression matches one of a number of _constant_ integer values, and branches accordingly". This from Kerninghan & Ritchie, Note the _constant_...
Best Wishes[/i] |
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Guest
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| Posted: Sun Oct 29, 2006 5:04 pm |
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Hi all,
As Ttelmah said, the switch is limited to constants.
BUT,
Here are some thoughts...
#1. Instead of variable within the switch, can you use "variables" that are defined within a "#define" statement?
| Code: |
#define TECLA_3_TV 62
.
.
.
switch(com)
{
case(TECLA_3_TV): bla bla bla
.
.
.
}
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#2. Don't use a switch!!! Can you use something like
| Code: |
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.
.
if(com==variable1) {// do variable 1 stuff}
elseif(com==variable2} { }
elseif(com==variable3} { }
.
.
.
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When you look at the logic of what you want, you are just comparing com with your variable.
#3. Good ol' pointers to functions!
| Code: |
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void (*pof)[10]; // array if 10 pof's
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pof[0]=&func1; // assign them manualy like this, or [better] Assign them in the def above
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pof[com](); // call it
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yes yes yes, this take memory if your index's are not seqencial
yes yes yes CCS does not support this...at least not v3x, I forget if v4x does... 
Well, thats food for thought
~Kam (^8* |
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kender
Joined: 09 Aug 2004
Posts: 768
Location: Silicon Valley
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| pointer-to-function... Mmmm... |
| Posted: Sun Oct 29, 2006 6:05 pm |
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| Anonymous wrote: | | yes yes yes CCS does not support this...at least not v3x, I forget if v4x does... |
v4.x should support pointer-to-function. It seems that this feature is being debugged by CCS. There's a lot of cool tricks that can be done with pointer-to-function... |
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Guest
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| Re: pointer-to-function... Mmmm... |
| Posted: Sun Oct 29, 2006 8:54 pm |
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| kender wrote: | | There's a lot of cool tricks that can be done with pointer-to-function... |
So true...so true...that opens up many programming techniques...pre oo progrmaming! CCS you're nearly a C compiler! 
~Kam (^8* |
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