How to print a char array in C through printf?

Question

This results in segmentation fault. What needs to be corrected?

int main(void)
{
    char a_static = {'q', 'w', 'e', 'r'};
    char b_static = {'a', 's', 'd', 'f'};

    printf("\n value of a_static: %s", a_static);
    printf("\n value of b_static: %s\n", b_static);
}

Solution 1

The code posted is incorrect: a_static and b_static should be defined as arrays.

There are two ways to correct the code:

• you can add null terminators to make these arrays proper C strings:

  #include <stdio.h>
  
  int main(void) {
      char a_static[] = { 'q', 'w', 'e', 'r', '\0' };
      char b_static[] = { 'a', 's', 'd', 'f', '\0' };
  
      printf("value of a_static: %s\n", a_static);
      printf("value of b_static: %s\n", b_static);
      return 0;
  }
  

• Alternately, printf can print the contents of an array that is not null terminated using the precision field:

  #include <stdio.h>
  
  int main(void) {
      char a_static[] = { 'q', 'w', 'e', 'r' };
      char b_static[] = { 'a', 's', 'd', 'f' };
  
      printf("value of a_static: %.4s\n", a_static);
      printf("value of b_static: %.*s\n", (int)sizeof(b_static), b_static);
      return 0;
  }
  

  The precision given after the . specifies the maximum number of characters to output from the string. It can be given as a decimal number or as * and provided as an int argument before the char pointer.

Solution 2

This results in segmentation fault. ? because of the below statement

char a_static = {'q', 'w', 'e', 'r'};

a_static should be char array to hold multiple characters. make it like

 char a_static[] = {'q', 'w', 'e', 'r','\0'}; /* add null terminator at end of array */

Similarly for b_static

char b_static[] = {'a', 's', 'd', 'f','\0'};

Solution 3

You need to use array instead of declaring

a_static
b_static

as variables

So it look like this:

int main()
{
  char a_static[] = {'q', 'w', 'e', 'r','\0'};
  char b_static[] = {'a', 's', 'd', 'f','\0'};
  printf("a_static=%s,b_static=%s",a_static,b_static);
  return 0;
}

Comments

[Jabari Dash]

char *a_static use a pointer

[Martin James]

See stackoverflow.com/q/33047452/758133

[Cœur]

Possible duplicate of Definitive List of Common Reasons for Segmentation Faults

[Aquarius_Girl]

Ah! Thanks for the fault.

[Anirudh]

You should also add the '\0' characters in your char array to prevent overflow.

[too honest for this site]

That's problematic and partially wrong in various places. For a start: pointers are never a replacement for arrays. If one feels like answering questions witrh broken code and lack of fundamentals like that, they at least should get it very correct so OP will not need to buy a textbook to learn the language properly which would be the correct way.