Handling a string constant as a symbolic const name

I guess this is a general C question... here's my code..

Code:

	OnCreate(hwnd,cs,initRecArea(480,45,55,20),(HMENU)IDCE_SINGLELINE5);
	OnCreate(hwnd,cs,initRecArea(480,105,55,20),(HMENU)IDCE_SINGLELINE7);
	OnCreate(hwnd,cs,initRecArea(480,135,55,20),(HMENU)IDCE_SINGLELINE8);
	OnCreate(hwnd,cs,initRecArea(480,165,55,20),(HMENU)IDCE_SINGLELINE9);
	OnCreate(hwnd,cs,initRecArea(480,195,55,20),(HMENU)IDCE_SINGLELINE10);
	OnCreate(hwnd,cs,initRecArea(480,225,55,20),(HMENU)IDCE_SINGLELINE11);
	OnCreate(hwnd,cs,initRecArea(480,255,55,20),(HMENU)IDCE_SINGLELINE12);

Since all these lines are a repetition except the second argument of initRecArea() which increments by 30, and last argument of OnCreate() which only has the last character changing, i would prefer looping this code as follows...

Code:

        char cnt;

	for (next=45, cnt=48;next<=255;next+=30, cnt++)	{
		sprintf(buffer,"%s%d","IDCE_SINGLELINE",cnt);
		OnCreate(hwnd,cs,initRecArea(205,45,55,20),(HMENU)buffer);
	}

but buffer is a string not a symbolic constant... How do i treat it as a constant? Or any other solutions to this?

No, you can't convert strings to variables or variables to strings - since variables names are lost during the compilation - they are only there for your benefit when writing the code. Once the compiler understands what's going on, variables become memory locations and/or registers.

You could do something like this:

Code:

HMENU table[] = { (HMENU)IDCE_SINGLELINE5, (HMENU)IDCE_SINGLELINE7, ... };
... 
        char cnt;

	for (next=45, cnt=0;next<=255;next+=30, cnt++)	{
		OnCreate(hwnd,cs,initRecArea(205,next,55,20),table[cnt]);
	}

A more flexible alternative would be to store the coordinates within the table as well.

--
Mats

Originally Posted by matsp

No, you can't convert strings to variables or variables to strings - since variables names are lost during the compilation - they are only there for your benefit when writing the code. Once the compiler understands what's going on, variables become memory locations and/or registers.

You could do something like this:

Code:

HMENU table[] = { (HMENU)IDCE_SINGLELINE5, (HMENU)IDCE_SINGLELINE7, ... };
... 
        char cnt;

	for (next=45, cnt=0;next<=255;next+=30, cnt++)	{
		OnCreate(hwnd,cs,initRecArea(205,next,55,20),table[cnt]);
	}

A more flexible alternative would be to store the coordinates within the table as well.

--
Mats

mhh... cool, thnx

Another trick you can do:

Code:

        char cnt;

	for (next=45, cnt=48;next<=255;next+=30, cnt++)	{
		OnCreate(hwnd,cs,initRecArea(205,45,55,20),(HMENU)IDCE_SINGLELINE + cnt);
	}

If IDCE_SINGLELINEX series are numbers after each other, like
#define IDCE_SINGLELINE45 45
#define IDCE_SINGLELINE46 46
#define IDCE_SINGLELINE47 47
#define IDCE_SINGLELINE48 48
Or the like, then the above code could work.

Originally Posted by Elysia

Another trick you can do:

Code:

        char cnt;

	for (next=45, cnt=48;next<=255;next+=30, cnt++)	{
		OnCreate(hwnd,cs,initRecArea(205,45,55,20),(HMENU)IDCE_SINGLELINE + cnt);
	}

Elysia, i doubt if IDCE_SINGLELINE + cnt will concatenating IDCE_SINGLELINE with the values in cnt, rather will add them together... Note also that cnt is a char, not int.. so char cnt =48 could represent the character value 0, 49 character 1, and so forth....

Originally Posted by csonx_p

Elysia, i doubt if IDCE_SINGLELINE + cnt will concatenating IDCE_SINGLELINE with the values in cnt, rather will add them together... Note also that cnt is a char, not int.. so char cnt =48 could represent the character value 0, 49 character 1, and so forth....

No, what elysia intends is to have a define for the base-number, and then just add the appropriate number to it.

Code:

#define IDCE_SINGLELINE     0 // Use the correct number here.

It does assume that the IDCE_SINGLELINEXX are sequential, which they may not be if they are generated by the resource editor and not added all at once.

--
Mats