How can I add a string to an array of strings in C?-CodePudding

I have a string "token" and an empty array of strings "arr". I want to add token to the first index of arr. I've tried arr[0][0] = token, but this would only work for chars and I've also tried arr[0] = token but this throws the error "expression must be a modifiable lvalue". My full program is:

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

char arr[100][100] = {};
char *token = strtok(StringToBeSplit, " ");
int i = 0;

while(token != NULL) {
    arr[0] = token;
    printf("%s\n", token);
    token = strtok(NULL, " ");
    i  ;
}

What should I do?

CodePudding user response：

You need to copy the string instead of assigning it. The other problem with your code is that only element [0] of the array ever gets populated

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

char arr[100][100] = {};
char *token = strtok("split this string", " ");
int i = 0;

while(token != NULL) {
    strcpy(arr[i], token);
    printf("%s\n", token);
    token = strtok(NULL, " ");
    i  ;
}

// At this point, i contains the number of tokens.

If you started i at -1 and incremented before the strcpy, then i would be the index of the last element.

CodePudding user response：

You need to avoid assigning string literal to strtok. Basically using strcpy to copy the token to array and increment array as advised by previous answer. Something like this:-

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

int main(){

char arr[100][100] = {};
char str[] = "Split this string";
char sep[] = " ";
char *token = strtok(str, sep);
int i = 0;
while(token != NULL){
    strcpy(arr[i], token);
    token = strtok(NULL, sep);
    i  ;
}

//Test If it can print the strings
for(int j = 0; j < i; j  )
    printf("%s\n", arr[j]);

 }