char ch[2];
ch[0] = 'h';
ch[1] = '';

char ch[1];
ch[0] = 'h';

char ch[2] = "h";

char ch[2] = {0};
ch[0] = 'h';

char ch = 'h';

char somestring[100];
char pos = 0;
while( ... ) {
    somestring[pos] = 'x';  /* or whatever */
    pos = pos + 1;
}
somestring[pos] = 0;

int ind=0;
while(...)
{
    ch[ind++]='h';
}
ch[ind]='';