Thread: using putchar()

Originally Posted by christop

If chara1 is an array of strings, then you're trying to add two pointers, which doesn't make any sense (C doesn't support string concatenation using the "+" operator like some languages).

putchar writes a char to stdout. That doesn't seem like the function you want.

strcat concatenates a string to the end of another string. If you want to "put" a character in front of a string, you'll need to move all characters in the string forward and then set the first character to the new character:

Code:

// untested
// s is the string, c is the char
// make sure the buffer holding the string s is long enough to hold another character before doing this:
memmove(s + 1, s, strlen(s) + 1); // +1 for the terminator
s[0] = c;

You have no error checking for the length of the string and the size of the array.

A better way of doing this, providing some error checking in the actual code:

Code:

#include <stdio.h>

int main(void)
{
  char ch = 'A';
  char src[64] = "This is a test.";
  char dest[128] = "";

  sprintf(dest, "%c%s", ch, src);
  printf("Final: [%s]\n", dest);

  return 0;
}

After prepending the character to the string, the combined dest string could be copied back to the src array, using strcpy()

I consider this safer considering the level of experience of the O/P.

its maybe easier to show you what im doing =]

the current output is:

0
01
012
0123
01234
012345
0123456
01234567
012345678
0123456789

which is correct

the problem is, I am trying to find a way to assign the array in the right order without having to use the strrev() function

any help?

Code:

    int i;


    int int1[10];
    char chara1[11][11] = {0};
    char chara2[10][10];
    


    for(i=0;i<10;i++){


        int1[i] = i; 
        itoa(int1[i],chara1[i],10);//convert number from int to string




        strcat(chara1[i],chara1[i-1]);//Concatenates from previous array number
        strcpy(chara2[i],chara1[i]);//copying array otherwise it would get scrammbled
        strrev(chara2[i]);//reverses string because 'strcat(chara1[i],chara1[i-1]);' puts the char behind the string instead of infront




        printf("%s\n",chara2[i]);




    }