Question

hi I am new here and new in Java programming as well actually my problem is that I have a Array List of type Book in which I am storing Book name and title and set the OnLoan value explicitly by true or false but I am able to store true or false value for the Book arrayList but I want to count number of true value in my arrayList say if 3 books having borrowed status true I want the count as 3 I dont know how to get that count out from ArrayList in java please help me out here is my sample code I am getting the true value by calling the getOnLoanStatus() from book class which holds true and false values

int borrowCount=0;
     Book loanStatus = new Book();
     boolean l = loanStatus.getOnLoanStatus();
     //boolean to String conversion

     System.out.println("value of l is" + l);
     if(this.booksHeld.isEmpty()) 
      {
        return null;
      }
       for(int i=0;i<this.booksHeld.size();i++)
       {
         if(booksHeld.contains(l)) // compare the isbn string with getIsbn Method
         {
             borrowCount++;
         }
       }
        if(borrowCount==0) 
        {
            return "Libray: " + numberOfBooks() + "books " +  " 0 book on Loan";
        }
        else
        {
          return "Libray: " + numberOfBooks() + "books " + borrowCount + "on Loan";
        } 

Answer 1

You can use a for-each loop, and check for each element if it is borrowed [assuming Book has a method onLoanStatus() which indicate if it is on load or not]

Should look something like that:

int count = 0;
for (Book b : booksHeld) { 
  if (b.getOnLoanStatus()) count++;
}
//now count holds the number of loaned books.