Hi,
I'm programming (Well mostly someone else is programming) PICs and I keep coming across CASE
I can understand English words like FOR and NEXT but when it comes to CASE, it doesn't sink in.

Can someone describe it in a simple way, so that I can understand and use it please?
Camerart.

 

hi C,
Select Case X
Case 0
do this one
'exit the Case test
Case 1
do this one
'exit the Case test
End Select

Its a simple way of avoiding writing multiple IF statements.

So if X = 0 do this
if X = 1 do this
if X= 2 do this one

OK.???
E

 

hi C,
Select Case X
Case 0
do this one
'exit the Case test
Case 1
do this one
'exit the Case test
End Select

Its a simple way of avoiding writing multiple IF statements.

So if X = 0 do this
if X = 1 do this
if X= 2 do this one

OK.???
E

Hi E,
Not really! I have this type of thing in my programs, perhaps written by you, but to me it reads like a foreign language.
If you were writing a Programming dictionary, how would you describe CASE, without examples?
C

 

Hi C,

if the value = this value then do this code
if the value = this value then do this code
if the value = this value then do this code

You are over thinking the problem, if the value matches one of the values in the Case list, do that Code and don't test any others in the Case List, until the next time you visit the Case list
E

 

As an approximation, think "circumstance" when you see 'CASE'.

 

Hi C,

if the value = this value then do this code
if the value = this value then do this code
if the value = this value then do this code

You are over thinking the problem, if the value matches one of the values in the Case list, do that Code and don't test any others in the Case List, until the next time you visit the Case list
E

Hi E,
True I am thinking alot about it, and I need to understand it, to sort out the problem in my programs, but at the moment It's baffling. EDIT: I have to understand something to use it
Thanks.
C

 

hi,
Consider a Street that has say 10 houses numbered from 1 to 10.
I give you a letter to post in house #3, you walk past houses 1 and 2 on the street until you come to #3, you post the letter [ or do the Code for #3]
Next time i see you I give you a letter for house number #7, you walk past houses 1 to 6 until you come to house #7, you post the letter [ or do the Code for #7]

 

As an approximation, think "circumstance" when you see 'CASE'.

Hi A,
In 'E's' last message this example [ if the value = this value then do this code ] I understand ok, but when I see 'CASE 0' for example, What does CASE mean and why 0. What's the difference between CASE 0 and CASE 1? At the bottom of the CODE I'm trying to understand, there is CASE ELSE, again, what does that mean in English?

I note that there is always a number e,g, 0 or 1 or 5. Are these binary, how big number can be used.

Circumstance. Is it similar to, 'in the first CASE', 'in the second CASE'? (First being 0)
C.

 

hi,
Consider a Street that has say 10 houses numbered from 1 to 10.
I give you a letter to post in house #3, you walk past houses 1 and 2 on the street until you come to #3, you post the letter [ or do the Code for #3]
Next time i see you I give you a letter for house number #7, you walk past houses 1 to 6 until you come to house #7, you post the letter [ or do the Code for #7]

Hi E,
Good example, I'll peruse it, thanks.
C

 

Hi E,
Good example, I'll peruse it, thanks.
C

Hi again E,
While perusing, I came across this Oshonsoft example:

I've commented it using how I see your 'house' example.
C.
-------------------------------------------
Dim x As Byte
loop:
Select Case x
Case 255 (At house 255 X=1)
x = 1
Case <= 127 (At houses 0 to 127 X=X+1)
x = x + 1
Case Else
x = 255 (At houses 128 to 254 X=255) (Assuming the houses stop at 255)
EndSelect
Goto loop
---------------------------------------------------

 

hi,
Case Else
Means if there is no match do this Code.
If I gave you a letter for house #11, no such house number so do this, >> take it back to the office [ Code]

 

hi,
Case Else
Means if there is no match do this Code.
If I gave you a letter for house #11, no such house number so do this, >> take it back to the office [ Code]

Hi E,
"Take it back to the office" and Let x=255
Edited
C.

 

The meaning of "case" in an English dictionary is: instance, occurrence, situation, existence.

Hence in a programming context, if the CASE of something occurs, then execute the following instructions.
ELSE would mean if no previously declared cases occurred, execute the following instructions.

 

For the following CASEs of this variable, execute the associated block of code.

CASE x // variable equals x​

int variable = 1;

select  case variable;

  case 0;
  // this block of code is executed 
  // if it’s the case that variable=0
  case 1;
  // this block of code is executed 
  // if it’s the case that variable=1

 

CASE is a computed GOTO in structured sheeps clothing.

http://www.lahey.com/docs/lfpro78help/F95ARComputed_GOTOStmt.htm

https://www.coridium.us/cHELP/scr/gcc/Labels-as-Values.html#Labels-as-Values

 

The meaning of "case" in an English dictionary is: instance, occurrence, situation, existence.

Hence in a programming context, if the CASE of something occurs, then execute the following instructions.
ELSE would mean if no previously declared cases occurred, execute the following instructions.

Hi Mr C,
So in #10 example is this correct:
Thanks, C.

-------------------------------------------------
loop:
Select Case x
Case 255 (At house 255 X=1)
x = 1
Case <= 127 (At houses 0 to 127 X=X+1)
x = x + 1
Case Else
x = 255 (If CASE 255 didn't occure and CASE <= 127 didn't occure then x=255)?
EndSelect
Goto loop
----------------------------------------------------

 

CASE is a computed GOTO in structured sheeps clothing.

http://www.lahey.com/docs/lfpro78help/F95ARComputed_GOTOStmt.htm

https://www.coridium.us/cHELP/scr/gcc/Labels-as-Values.html#Labels-as-Values

Hi N,
Thanks,
C.

 

For the following CASEs of this variable, execute the associated block of code.

CASE x // variable equals x​

int variable = 1;

select  case variable;

  case 0;
  // this block of code is executed
  // if it’s the case that variable=0
  case 1;
  // this block of code is executed
  // if it’s the case that variable=1

Hi D,
The first mention of a VARIABLE!
Helpful, thanks.
C

 

Hi,
Thanks to all, I think I may almost understand. I'll try some tests
C