On Sat, 20 Dec 2003 10:42:46 +0000, Adam Harper <a-news-d@harper.nu> wrote:
> On Sat, 20 Dec 2003 04:19:24 -0500, Lewis wrote:
> > One of the most confusing things for me in D or any C style language (curly braces and such) is the use of stars * here and there and what there placement means...
> 
> "*"'s are the pointer declaration/dereference character in C, C++ and D. They are also the multiplication operator.  The placement decides whether they are being used as one or the other.  Generally, the "*" means multiply when it doesn't:
> 
>     - Follow a type (e.g. "int *", "char *", etc.)
>     - Come before a pointer variable
> 
> Whitespace doesn't really matter.
> 
> To give you a code example:
> 
> > int i = 1;
> > int i2 = 2;
> > int* i_ptr = &i;  // "i_ptr" is a pointer to "i"
> >
> > i = i * i2; // i = i (multiplied by) i2
> > i2 = * i_ptr; // i2 = (The value pointed to by i_ptr)
> 
> To declare a pointer you place a "*" before the variable name, any of the following are valid pointer declarations:
> 
> > int* i;
> > int * i;
> > int *i;
> 
> To make the pointer actually point to something you need to assign it a reference, this is done by placing the "&" character before a variable name:
> 
> > int i = 123;
> > int* ptr = &i; // "ptr" points to "i"
> 
> To access the value pointed to by a pointer you need to dereference it, this is done by placing a "*" before the pointers name:
> 
> > printf( "%d", ptr ); // Will print the memory address that
> >                      // "ptr" points to, e.g. "-1073743116"
> > printf( "%d", *ptr ); // Will print "123"
> 
> 
> > for example i know that *MyString would indicate a pointer to MyString if my guess is correct.
> 
> "*MyString" is a pointer /called/ "MyString", not a pointer /to/ "MyString".  Pointers are just variables like everything else and they share the same namespace(?), so you can't have:
> 
> > int MyInt;
> > int *MyInt;
> 
> It's easier if you use the D type declaration [http://www.digitalmars.com/d/declaration.html] (which is also valid in C), where the "*" comes after the type instead of before the variable name:
> 
> > int* MyInt;
> 

But  'int* x,y"  is valid in both C and D but means entirely different things! D continually surprises me


>  <<snip>>

Karl Bochert