Java - 遍历数组列表并输出从最高到最低的数字？

Question

有没有办法让我可以对 ArrayList 输出进行排序，找到找到的最大数字和找到的最小数字？我现在的方式是一个“购物 list ”，其设置如下:

public void addToBag(String anyItem, int anyUnits, double anyCost){
    int checkUnits = anyUnits;
    double checkCost = anyCost;
    if(checkUnits < 0 || checkCost < 0){
        System.out.println("You must enter a value equal to or greater than 0!");
    }else{
    shoppingBag.add(new Item(anyItem, anyUnits, anyCost));
}
}

以及仅输出列表的输出

  public void calculateSalesReceipt(){
    System.out.println("Enter the sales tax percentage (ex. 0.08 for 8%) or type \"random\" for a random number: ");
    double tax = keybd.nextDouble();
    if(tax < 0){
        System.out.println("You must enter a value equal to or greater than 0!");
    }else{
    getPricePreTax();
    total = total;
    taxCost = total * tax;
    finaltotal = total + taxCost;
    System.out.println("Sales Receipt");
    System.out.println("-------------");
    for(Item currentProduct : shoppingBag){
        System.out.println(currentProduct.getName() + " - " + currentProduct.getUnits() + " units " + " - $" + currentProduct.getCost());
    }
    System.out.println("Total cost: $" + total);
    System.out.println("Total tax: $" + taxCost);
    System.out.println("Total cost with tax: $" + finaltotal);
    System.out.println("Do you have any coupons? Enter \"yes\" or \"no\"");
    String answer = keybd.next();
    if(answer.equals("yes")){
                applyCoupon();
            }else if(answer.equals("no")){
            System.out.println("Thank you!");
        }else if(answer != "yes" || answer != "no"){
            System.out.println("Thank you!");
        }
    System.out.println("Coupon discounts: $" + couponAmount);
    System.out.println("Grand total: $" + (finaltotal-couponAmount));
}
}

谢谢!

编辑:

这行得通吗？

 public void getLargest(){
    for(Item currentProduct : shoppingBag){
        System.out.println(Collections.max());
    }
}

Answer 1

您可能想要Collections.max() (分别是Collections.min())。如果您希望整个列表按顺序排列，您可能需要 Collections.sort()。