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cwhile-loopcharc-stringsfunction-definition

Can you help me find a problem with this basic C code

I'm solving some problems from a C programming book to brush up on Strings. I can't figure out why my solution is not working.

Question asks to write a function named censor that modifies a string by replacing every occurrence of foo by xxx.

My code:

int main()
{
    char msg[] = "I love food, you fool.";

    censor(msg);

    puts(msg);

    return 0;
}

void censor(char *str) {
    char *c = str;
    while (c+2 != '\0') {
        if (*c == 'f' && *(c+1) == 'o' && *(c+2) == 'o')
            *c = *(c+1) = *(c+2) = 'x';
        c++;
    }
}

I found that the while loop runs for like 1700 times. I'm pretty sure msg[] will include a null character automatically end of string.

Solution

  • You're checking the value of the pointer, not what it points to. So instead of this:

    while (c+2 != '\0') {

    You want this:

    while (*(c+2) != '\0') {