C char** 得到结果

Question

I want to get result by char ** , but the result is only one char, why? I don't want to use return char * to solve this question. who can tell me?

void test() {
    char A[] = "123,563";
    char *result = (char *)malloc(5*sizeof(char));
    addStringAtoB(A, &result);
    printf("\n result :----- %s \n", result); // result is not all, but one point ?
}

int addStringAtoB(char string[], char **result) {
    char* token = strtok( string, ",");
    char *stringA;
    if (token != NULL) {
        stringA = token;
        token = strtok( NULL, ",");
    }
    char *stringB;
    if (token != NULL) {
        stringB = token;
    }

    int lenA = strlen(stringA);
    int lenB = strlen(stringB);
    int len = lenA < lenB ? lenA : lenB; 
    char resultTem[1000] = {};
    for (int i=0; i<len; i++) {
        char a = stringA[i];
        char b = stringB[i];
        if (a >='0' && a <= '9' && b >='0' && b <= '9') {
            int c = (int)(a - '0') + (int)(b - '0');
            resultTem[i] = c + '0';
        }
        else {
            *result = "error";
            return 0;
        }
    }

    if (len == lenA) { 
        for (int j=len; j<lenB; j++) {
            resultTem[j] = stringB[j];
        }
    }
    else if (len == lenB) { 
        for (int j=len; j<lenA; j++) {
            resultTem[j] = stringA[j];
        }
    }
    **result = *resultTem; 
    return 0;
}

Answer 1

Your question is not clear and it is not well defined.

I arranged a little bit your code in a way that I consider it could be sufficient to answer to your question. Anyway, I left to you the correctness controls of your code.

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int addStringAtoB(char string[], char **result) {
    char* token = strtok( string, ",");
    char *stringA;
    if (token != NULL) {
        stringA = token;
        token = strtok( NULL, ",");
    }
    char *stringB;
    if (token != NULL) {
        stringB = token;
    }

    int lenA = strlen(stringA);
    int lenB = strlen(stringB);
    int len = lenA < lenB ? lenA : lenB; 
    char resultTem[1000] = {};
    int i=0;
    for (; i<len; i++) {
        char a = stringA[i];
        char b = stringB[i];
        if (a >='0' && a <= '9' && b >='0' && b <= '9') {
            int c = (int)(a - '0') + (int)(b - '0');
            resultTem[i] = c + '0';
        }
        else {
            *result = "error";
            return 0;
        }
    }

    if (len == lenA) { 
        int j=len;
        for (; j<lenB; j++) {
            resultTem[j] = stringB[j];
        }
    }
    else if (len == lenB) { 
        int j=len;
        for (; j<lenA; j++) {
            resultTem[j] = stringA[j];
        }
    }
    *result = resultTem; 
    return 0;
}

int main() {
    char A[] = "123,563";
    char *result = (char *)malloc(5*sizeof(char));
    (void)addStringAtoB(A, &result);
    printf("\n result :----- %s \n", result); // result is not all, but one point ?
    return 0;
}