pointer to char array

[harish9]

*ptr = 'hello world";

if we try to modify the content the result is undefined when i worked with gcc in unix.
But i can modify the content in Turbo c. How it worked i got confussed.

[gerard4143]

When you have a pointer defined like so

char *ptr = "hello world";

It creates a read only character pointer. If you require a char array that's writable then use.

char ptr[] = "hello world";

[rubberman]

This is one of those things that the standards allow implementations to "do their own thing" on. A string literal may (or may not) be in read-only memory as a constant. So, gerard4143 is absolutely correct if you want to modify the contents of the string in a platform-neutral manner. Neither gcc nor Turbo are breaking the rules. It's just that the rules are flexible in such cases. Caveat Programmer! :-)

[harish9]

thanku for ur information. I know it is stored in read only memory and i also know that we can't alter a value but how it worked in Turbo C thats my question.

[gerard4143]

thanku for ur information. I know it is stored in read only memory and i also know that we can't alter a value but how it worked in Turbo C thats my question.

Why it worked in Turbo C, read Rubberman's post.

[Narue]

if we try to modify the content the result is undefined when i worked with gcc in unix.

Correction: the result is always undefined, regardless of compiler. Whether it "works" or not depends on how the compiler implements string literals and enforces modification. Even if it "works", you could still be creating a subtle error down the line.

The lesson to be learned is don't rely on undefined behavior.

[quynyth]

I am not familiar this topic of C language but I have backgrounds on some basic from the language. I hope you can help me with this topic.

basic math test

[gerard4143]

I am not familiar this topic of C language but I have backgrounds on some basic from the language. I hope you can help me with this topic.

basic math test

What is this?

[rubberman]

What is this?

Trolling I think.