How to combine three char to one

Question

I had three char inside the array , which contain X1 X2 and X3

char array[3]={X1,X2,X3}

I want to combine three data which inside the array to one char

strcat(array[0]," ");
strcat(array[0],array[1]);
strcat(array[0]," ");
strcat(array[0],array[2]);

printf("%s",array[0])

I expect to get the result like this "X1 X2 X3"

Answer 1

I think you mean you want to concatenate 3 chars to a make one string.

Use sprintf with a sufficient array:

char str[6];
char array[3] = {'l', 'o', 'l'};

// write
sprintf(str, "%c %c %c", array[0], array[1], array[2]);

// print
printf(str);

Answer 2

you will need one more byte to have a null terminator.

char array[4] = { 'a', 'b', 'c', '\0' };
printf( "%s\n", array );

will give your abc

Answer 3

You can't do it that way. array is only 3 bytes long, so you can't have the string "a b c", which is 5+1 = 6 bytes long in it. And, of course, you can't call strcat(array[0], ... since array[0] is a single char, not a char *.

I'm not sure what you are looking for, but if you are given X1, X2 and X3 and want them in a string separated by spaces, you can do that :

void chars2str(char x1, char x2, char x3, char* dest) {
    sprintf(dest, "%c %c %c", x1, x2, x3);
}

Of course, the dest argument must be big enough or something very nasty might happen.

char mystr[6];

char2str('a', 'b', 'c', mystr);  /* Now mystr contains "a b c" */

Answer 4

The way you're using strcat is incorrect. array[0] is a char, which means it can hold only a single letter. It cannot hold X1 along with a " " or X2. Create another sufficiently big char array and then you can strcat to that.

Answer 5

#include <stdio.h>

char *join(char *result, const char array[], size_t size, const char sep){
    size_t i,len=0;
    for(i=0;i<size;++i){
        len+=sprintf(result+len, "%c", array[i]);
        if(i < size - 1)
            len+=sprintf(result+len, "%c", sep);
    }
    return result;
}

int main(void){
    const char array[] = { 'x', 'y', 'z'};
    char result[6];

    join(result, array, sizeof(array)/sizeof(char), ' ');
    printf("%s", result);//"x y z"
    return 0;
}

Answer 6

You could convert each individual char to a string, then concatenate them.

e.g.

    char c = 'c';
    char d = 'd';
    string s1(1, c);
    string s2(1, c);
    string cd = s1 + s2;