char *

[dasman]

char *s = "abcd";
creates a char pointer that points to beginning of "abcd".

why does my program crash when I do this
*s = 'z';

I suspect it crashes because I try to access some part of memory I am not supposed to, but I dont understand it.

[Athar]

String literals are constant character arrays.
As such, you cannot assign their address to a char* pointer. The line you posted should not compile. If it does, get a new compiler, yours is probably ancient.

const char* s = "abcd";
would be correct.

String literals are usually in read-only parts of memory, so that explains why in your case the program still crashes on the second line, even though the compiler let the first one pass (wrongly).

[Bazzy]

You can however use string literals to initialize an array: char s[] = "abcd"; in this way, you can modify them

[vivmen]

you might using visual studio, in visual studio char * s = " " is consider as a const string

& trying to change it gives runtime error , ( i think it is access violation 0x0000005 i am not

sure )
try
char arr[] = "";

hope it helps

[binarybob350]

Declaring the following and then changing it is bad practace. If you copy a string more than 4 characters into s you will corrupt the stack.

char s[] = "abcd";

You should use either CString (if in VS) or STL string class.