确定 arraylist2 的输入是否存在于 arraylist1 中，因为它们被放入

Question

I'm making a program where an arrayList (list1) is made beforehand, and then as the values for list2 are being entered, I want to see if that value already exists in list1.

Here's what I'm trying to do: Just for practice, I want to make a program for truck day at work. Before the truck arrives, a list of what items can fit on shelves (list1) is made. As each box is unloaded off the truck, the code for it is scanned and added to list2, and if that code appears on list1, I want it to print out "Out to shelf." or something similar. If the incoming boxes code does not appear on list1, do nothing and continue accepting values to add on to list2. However, I can only figure out how to compare the lists AFTER they've been made, but it is important to compare them AS list2 is being created.

//get bin list codes
        System.out.println("Enter bin list codes, type in 0 when finished!");
        int binCode = input.nextInt();
        while (binCode != 0) {
            binList.add(binCode);
            binCode = input.nextInt();
        }

//get truck list codes
        System.out.println("Enter truck list codes, type in 0 when finished!");
        int truckCode = input.nextInt();
        while (truckCode != 0) {
            truckList.add(truckCode);
            truckCode = input.nextInt();
        }

//print out bin list
        for(int i : binList) {
            System.out.println(i);
        }
        System.out.println("--------");

//print out truck list
        for(int i : truckList) {
            System.out.println(i);
        }
        System.out.println("--------");
    }

Answer 1

Try this perhaps:

//get truck list codes
System.out.println("Enter truck list codes, type in 0 when finished!");
int truckCode = input.nextInt();
while (truckCode != 0) {
    if(binList.contains(truckCode)) {
        //do your print out here
    }
    truckList.add(truckCode);
    truckCode = input.nextInt();
}