C / C++ / MFC

DavidCrow wrote:

Hard-coding numbers (e.g, 30) is usually not a good thing.

James R. Twine wrote:

Usually?

foo(char Name[30]);

DavidCrow wrote:

I was erroring on the side of "there might be an exception." I know of no reason to use:

foo(char Name[30]);

especialy if multiple of them exist. Once the size of the variable changes, every function prototype would also have to be changed.

void    foox( char caData[ 30 ] ) { TRACE1( "foo %s\n", caData ); }
void    foox( char *cpData ) { TRACE1( "foo2 %s\n", cpData ); }
void    foox( char cvData[] ) { TRACE1( "foo3 %s\n", cvData ); }

void    foo( char caData[ 30 ] ) { TRACE1( "foo %s\n", caData ); }
void    foo2( char *cpData ) { TRACE1( "foo2 %s\n", cpData ); }
void    foo3( char cvData[] ) { TRACE1( "foo3 %s\n", cvData ); }
 
    char    *cpTest = "Test";
    char    caTest30[ 30 ] = { "Test" };
    char    caTest10[ 10 ] = { "Test" };
    char    cvTest[] = "Test";
 
    foo( cpTest );    foo( caTest30 );
    foo( caTest10 );  foo( cvTest );
     
    foo2( cpTest );    foo2( caTest30 );
    foo2( caTest10 );  foo2( cvTest );
 
    foo3( cpTest );    foo3( caTest30 );
    foo3( caTest10 );  foo3( cvTest )

<HR>

struct Stru_A
{
    char Name[30];
    int Age;
    Stru_A::Stru_A()
    {
        Age = 0;
        memset(Name,0,30);
    }
}

<br />
<br />
struct Stru_A{<br />
Stru_A(char Name[30], int Age) <br />
{<br />
<br />
strcpy(this->Name, Name);<br />
this->Age = Age;<br />
}<br />
char Name[30];<br />
int Age;<br />
<br />
}*pStru_A;<br />
<br />
<br />
pStru_A xyz = new Stru_A("ABC", 123);<br />
<br />

struct Stru_A{
    char Name[30];
    int Age;
    Stru_A::Stru_A() 
    {
        memset(Name, 0, 30);
        Age = 0;
    }

    Stru_A::Stru_A(char* inName, int inAge) 
    {
        memset(Name, 0, 30);    // this insures a null terminator
        strncpy(Name, inName, 29);
        Age = inAge;
    }
}*pStru_A;

pStru_A xyz = new Stru_A("ABC", 123);

krmed wrote:

Note also that you should use strncpy to be sure the copy doesn't overwrite the 30 character size you have, and still leaves space for the null terminator.

Maximilien wrote:

be certain that it's not there when you create it.

Like2Byte wrote:

6020
AlphaEntry
What gives?