[bh_letters]

hi
whats the difference between const char* and char*? i need to append data (data varies in size) to char array and then write it to a text file. which one of these serves the purpose.

thanks in advance

[infamous41md]

a const char * is a pointer that always points to the same location i believe. a char * is just a regular pointer to a character. you should use a regular char * for your needs

[clifford]

Declaring a parameter const char*prevents the function being called from moving the pointer. The data pointed to however may be changed. In C++ a reference parameter
char& does a similar job and may be clearer. A char* will work, but the protection is not there, and does not indicate intent to the user of the function.

Clifford

[Scorpions4ever]

Originally posted by clifford
Declaring a parameter const char*prevents the function being called from moving the pointer. The data pointed to however may be changed. In C++ a reference parameter
char& does a similar job and may be clearer. A char* will work, but the protection is not there, and does not indicate intent to the user of the function.

You're confusing const char * and char * const declarations. You can move the const char * ptr, but you can't assign to the data being pointed to (if you couldn't move the pointer, strcpy(), strcmp() etc. would never work). See What's the meaning of: int const *pt for a slightly long winded explanation about different declarations using const.

[clifford]

I was going to argue that point, but had the sense to check, and Scorpions4ever is entirely correct.

From Stroustrop:

char *const cp    // const pointer to char
char const* pc    // pointer to const char
const char* pc    // pointer to const char

Clifford