if i have a char* such as str2 and str3 is it neccassary to create a memory with the new operator or can i do it just by assigning string constants to them? int l; char* str2; char* str3; str3="test this one"; l=strlen(str3); str2=new char[l+1]; strcpy(str2,str3); or str3=str2; is there an advantage or disadvantage to doing it either way? I am using MSVC++ 6.0 if that makes a difference.

The difference between strcpy(str2, str3) and str2=str3 is that in the former case str3 and str2 point to *different* strings that just happen to have the same contents. In the latter case str3 and str2 point to the *same* string.

Consider what happens in each case if you then do:

str2[0] = ''x'';

In the strcpy case str2 is now "xest this one" and str3 is unchanged. In the str2=str3 case you''ll either crash because str3 (and str2) is read only or both str2 and str3 will see the change.

-Mike

Actually i tested it out on my compiler for the str2=str3 case and both strings kept different addresses...so i could still modify them independently...my real question was about using the new operator to create a memory space for a char* as opposed to simply assigning str2="stuff";

i know that str2=str3 keeping seperate addresses doesnt make since due to the fact they are both pointers but...the only thing i can think of is its something specific to this compiler.

Weirdly, with some implementations (and I think MSVC++6) when you declare the same text withing a char*, you are using the same address. For instance:

char* str1 = "Hello, its a nice day";
char* str2 = "its a nice day";

"its a nice day" is the same address in str1 and str2, but "Hello," stays individual. Now say you changed str1 to: "Hi, what a great day!" then you can see how this would affect str2. Don''t ever change a char*! If you wanted to change a char*, create some memory in the free store with the new keyword.

The ''merging'' of two identical strings is not implementation dependent, it''s a compiler option. I''m sure you can change it under Borland C++ (''Merge duplicate strings''), but I haven''t seen it with VC++. I think it''s done when using the "optimize for minimal size" option.

Dormeur