How can I overwrite an array of chars (AKA a string), with a new array of chars in C?

int main(void) {
  ...
  char A[32] = "00000000000000001111111111111110"; 
  ...
  A = "11111111111111111111111111111111";
}

This is erroneous c-code for what I want to do. I want the string开发者_运维百科 in memory to be overwritten with a new string of the same length. I keep getting incompatible types -like errors.

Use strncpy:

char chararray[6];
(void)strncpy(chararray, "abcdefgh", sizeof(chararray));

Use strcpy(char *destination, const char *source);.

#include <string.h>

int main(void) {
  ...
  char A[32] = "00000000000000001111111111111110"; 
  ...
  strcpy(A, "11111111111111111111111111111111");
}

Though safer is strncpy(char *destination, const char *source, size_t num), which will only copy num amount of characters, preventing going out of bounds on the destination:

#include <string.h>

int main(void) {
  ...
  char A[32] = "00000000000000001111111111111110"; 
  ...
  strncpy(A, "11111111111111111111111111111111", sizeof(A));
}

memcpy(A,"11111111111111111111111111111111",32);

Among other possible ways, you can do

memcpy(A, "11111 etc.", 32);

You want to make 32 into a named constant, at the least. You also have to be careful of buffer overflows; in C this is not checked.

have a look into the library function strcpy.