check if a char exists in a char 2 dimensional array - c

Question

I'm trying to check if a character belongs to a two dimensional array of characters, but my code doesn't work right for all characters. I think that something goes wrong with my pointer.For example if i change 'b' to 'r' it doesn't work correctly.
Thanks in advance.
#include <stdlib.h>
#include <string.h>
int main(int argc, char *argv[]) {
char *pch;
char matrix[2][2]={
"best","cover",
"orbit","boost"
};
pch=strchr(matrix,'b');
if (pch==NULL)
{
printf ("not exists");
}
else
{
printf("exists");
}
return 0;
}

Answer 1

There are three problems in your code.
You need to include <stdio.h> in order to use printf.
There isn't enough memory allocated here:
char matrix[2][2]={
"best","cover",
"orbit","boost"
};
You give space for two strings each of which can hold 1 character(+1 for the NUL-terminator at the end).
Fix it by using:
char matrix[4][6]={
"best","cover",
"orbit","boost"
};
The six is the maximum number of characters in a string + one for the \0 at the end and the four is the number of maximum number of strings in the 2D array.
strchr expects the first argument to be of type const char*. You give the argument matrix which is of type char(*)[2]. You need to loop and find if the character is in each string of the array of array of chars.
After fixing these problems, your code will be:
#include <stdlib.h> // Not required
#include <string.h> // For strchr()
#include <stdio.h> // For printf()
int main(int argc, char *argv[]) {
char *pch;
char matrix[4][6]={
"best","cover",
"orbit","boost"
};
int i;
for(i=0;i<4;i++)
{
pch=strchr(matrix[i],'b');
if (pch==NULL)
{
printf ("not exists in %s\n",matrix[i]);
}
else
{
printf("exists in %s\n",matrix[i]);
}
}
return 0;
}