String is adding special characters

Question

I started following tutorials on C, and then I (from scratch) attempted to do a program where the program chooses a word and you have to guess letters, until you find out the word or run out of attempts.

But I am stuck at the string part, really weird :

srand(time(NULL));
char pWord[6][15] = {"chocolate","peanut","bowling","helicopter","school","controller"}; // Possible words
int repeat=0;
int rNum = rand()%6;
char solution[strlen(pWord[rNum])];
while(repeat<strlen(pWord[rNum])) {
    solution[repeat]=pWord[rNum][repeat];repeat++;  
}
printf("Answer : %s", solution); printf("\n");
printf("R Answer : %s", pWord[rNum]); printf("\n");
printf("R length : %i", strlen(pWord[rNum])); printf("\n");
strcpy(solution,pWord[rNum]);

For bowling it is fine, but for others it adds weird special characters at random.
I have no idea why this is happening ( i come from java, somewhere lazy and easy ).

Answer 1

In C, the string ends with null character '\\0' . So when you declare the character string solution , you need to add one to the length of the char array since strlen() function doesn't count the null character at the end.

char solution[strlen(pWord[rNum])+1];

Then after the while loop, you need to assign the '\\0' to the last element of the char array:

while(repeat<strlen(pWord[rNum])) {
    solution[repeat]=pWord[rNum][repeat];
    repeat++;  
}
solution[repeat]='\0';

A better way to do this string copying is to use strcpy() function instead of the while loop:

strcpy(solution, pWord[rNum]);

This way you don't have to assign the null character to the last character. This function does it for you.