CODEWITHSUNDEEP
cdebuggingpointerslinked-liststrcmp
Deniz Cetinalp
Deniz Cetinalp

Reputation: 911

Getting contains function of linked list to work properly in C

I implemented a linked list with a contains function. It uses strcmp like so:

    void contains(NODE *head, char data)
{
    NODE *this = head;
    while(this != NULL && strcmp(this->data, data) != 0)
    {
        if(strcmp(this->data, data) == 0){
            printf("Found data %s\n", this->data);
        }
        this = this->next;
    }
}

in main I have (I use contains on the last line):

NODE *head;
head = malloc(sizeof(NODE));

bool headNode = true;
char userID[1000];
char test[180] = "monkey"; // for testing contains function
while((fgets(userID,1000,stdin) != NULL)){
    if(headNode == true)
    {
        head = insert(NULL, userID);
        headNode = false;
    }
    else
    {
        head = insert(head, userID);
    }
}
contains(head, test);

I am still learning C, pointers are still a bit confusing. I have a feeling im making a basic mistake. I want to let the user input some string on their own and check if the list contains that string, but I cant even get contains to work with this test string. I know what I am comparing the test string to is indeed in the list, I have a printList function which I used to verify.

Upvotes: 0

Views: 461

Answers (2)

Sunil Bojanapally
Sunil Bojanapally

Reputation: 12658

test is an pointer to an array which you are passing in function contains(head, test);, So formal argument in the caller function should be a pointer as, contains(NODE *head, char * data) { ....

Upvotes: 1

Jerry_Y
Jerry_Y

Reputation: 1734

Pass in the pointer "test" into function "contains()":

It should be:

void contains(NODE *head, char * data)

Upvotes: 1

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