Class and string problems

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November 23rd, 2002, 05:44 PM

Marky_Mark

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Class and string problems

Can anyone help i have a problem with passing a string from one class to another

Code:



//Ok im in my first class and want to pass a string array to my printer class



// string array
char aMsg[] = "My string";
		 

// call my second class
MysecondClass second;
second.print_msg(&aMsg);



// function in second class
void MysecondClass::print_msg(char *ptr){

// do whatever
		
}

It's not working but i cant see anything wrong

Any ideas?

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Last edited by Marky_Mark : November 23rd, 2002 at 05:47 PM.

November 24th, 2002, 04:39 AM

M.Hirsch

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first, "it´s not working" is very vague...

second, it´s a char-array, not a string array.

did you try "second.print_msg(aMsg);" without the ampersand? afaik arrays are always passed by reference, never on the stack, this makes an implicit "&" even if you don´t supply it.

and: why don´t you make it a char* (the commonly used type for strings in C unless you have a "real" String class) - this will save you from most type-juggling fun

char *aMsg = "My string";

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Last edited by M.Hirsch : November 24th, 2002 at 04:41 AM.

November 24th, 2002, 10:17 AM

Marky_Mark

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Tried passing the string array without ampersand and i still keep getting this error

error C2143: syntax error : missing ';' before '.'

Code:



// call my second class
MysecondClass second;


// error line
second.print_msg(aMsg);



// this is the print function in second class
void MysecondClass::print_msg(char *str){
}

Is char *str correct to recieve the address of the incomming array

Last edited by Marky_Mark : November 24th, 2002 at 10:20 AM.

November 24th, 2002, 10:24 AM

M.Hirsch

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yes. it is correct.

Quote:

// call my second class
MysecondClass second;
// error line
second.print_msg(aMsg);

there is no ";" missing. your compiler is broken or you didn´t supply enough code. (probably the second option, but please don´t post the whole code. check for missing brackets.)

on the other hand, i am no c++ pro, but i only know of this syntax to instanciate and access classes:

MysecondClass *second=new MysecondClass();
second->print_msg(aMsg);

but your syntax should be correct too imho.

November 24th, 2002, 12:00 PM

Marky_Mark

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Thanks for your help

I located the problem to a naming error

I was using

Code:



Interface GUI;
GUI.Display(string);

That looks fine but MSVC++ throws an for using GUI as a reference

Last edited by Marky_Mark : November 24th, 2002 at 12:03 PM.

Class and string problems

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