Строковые константы - Too many initializers for 'char []'

void main()
{
  char *str[] = {"This is","Char constant",NULL};
  char *p;
  p = str;
  printf("%c\n",p[1]);
}

void main()
{
  char str[] = {"This is","Char constant",NULL};
  printf("%c\n",str[1]);
}

int main() {
    const char* str[] = {"this is", "String constant"};
    printf("%s\n", str[1]);
    return 0;
}

char str[] = {'a','b','c'};

char str[] = "This is char constant";

#include <stdio.h>
#include <string.h>
 
char *p = "тестовая строка";
 
int main(void)
{
  register int t;
 
  /* печать строки слева направо и справа налево */
  printf(p);
  for(t=strlen(p)-1; t>-1; t--) printf("%c", p[t]);
 
  return 0;
}

const char *p = "тестовая строка";

 char str[10],*p;
str[2] = 123;
p = &str[2];
printf("%d",*p);

 char str[10],*p;
p = str;
p[2] = 123;
printf("%d",*(p+2));

 char *p ='A';
 int main()
{
  printf("%c",p); // error invalid conversion from 'char' to 'char*' [-fpermissive] char *p = 'A';
   printf(p); // error...
}