C printf格式

Question

I have the following function to print a list of books borrowers have taken out.

void searchBorrowerLoans(int a) {   
            int i;
            for (i = 1 ; i < MAX_BOOKS ; i++) {                 
                if (loanlog[i].borrowerid == a) {
                    NEWLINE;
                    printf("Borrower ID : %i <--Borrowing-> Book ID's : %i\n", loanlog[i].borrowerid, loanlog[i].bookid);
                }
            }
        }

I want to be able to format the results like this

 Borrower ID : 5 <---Borrowing---> Book ID's : 5, 3 , 2

Instead of (New line)-

 Borrower ID : 10 <--Borrowing-> Book ID's : 5

 Borrower ID : 10 <--Borrowing-> Book ID's : 7

 Borrower ID : 10 <--Borrowing-> Book ID's : 8

 Borrower ID : 10 <--Borrowing-> Book ID's : 9

Answer 1

I don't know what NEWLINE is, but it's not necessary to know, just do it like this

printf("Borrower ID : %d <--Borrowing-> Book ID's :", a);
for (i = 0 ; i < MAX_BOOKS ; ++i)
 {
    if (loanlog[i].borrowerid == a)
        printf("%d, ", loanlog[i].bookid);
 }
printf("\n");

note that I fixed the loop to start from i = 0 because usualy in c that would be correct since arrays ire indexed from 0 not from 1 .

You will have to deal with an extra , at the end of the book id list.