Thread: Pointers help please(using pointers to copy a string)

question A: in the while loop we have,"*pB++ = *pA++; " to copy the contents of strB to strB, why is the entire string copied because *ptrA++ insures that it starts from the second character in the string does it not?? please explain this.questionB:the size of strB is obviously to small to accept the contents of strA yet it does, ? can some one please explain why

Code:

#include char strA[80] = "A string to be used for demonstration purposes";char strB[1];int main(void){          char *pA;              // a pointer to type character           char *pB;              // another pointer to type character           puts(strA);            // show string A           pA = strA;             // point pA at string A */          puts(pA);              // show what pA is pointing to */          pB = strB;             // point pB at string B          putchar('\n');          while(*pA != '\0') {      //copies strA tp strB                 *pB++ = *pA++;          }         *pB = '\0';                   // adds the nul terminator to strB          puts(strB);           return 0;}

'*ptrA++ insures that it starts from the second character in the string does it not?' no it does not. the postfix ++ increments the pointer AFTER the assignment. but thats not your problem. you are just overwriting the memory that follows wherever strB is located. C doesn't protect from overwrites like that. you can happily corrupt memory all you want. you have to deal with the length of the destination string yourself, with a counter or something. look at the definitions of 'strcpy' and 'strncpy' to see an example.