java - 需要在 java 中打印 2 个小数位而不是 1 个(特定实例)

Question

我目前有一个代码可以正常工作(多次编译和测试)但是我正在输出:

Card Balance: $500.0
Minimum payment to principle (3% of principle): $15.0
Minimum total payment (payment and fees): $60.0

我需要这些值以 2 位小数而不是 1 位小数打印出来(500.00 而不是 500.0)。我知道这很简单，但到目前为止没有其他论坛帮助过我 - 当我尝试 printf 时出现转换错误，当我尝试 DecimalFormat 时出现 DecimalFormat 不存在的错误。我只是不知所措，将不胜感激任何帮助。我将在下面包含所有相关代码(但出于相关性问题，我不会添加所有其余代码)。

    //Declaration
    double bal = 0;
    double intrst = 0;

    //Captures input
    Scanner scan = new Scanner(System.in);
    System.out.print("Current Balance: ");
    bal = scan.nextDouble();

     //Just explains intrst value
    if(late == true)
    if(lvl.equalsIgnoreCase(royal)) intrst = .022;
    else if(lvl.equalsIgnoreCase(gentry)) intrst = .028;
    else if(lvl.equalsIgnoreCase(common)) intrst = .03;
    else
   {
    System.out.println();
    System.out.print("Unknown customer level ");
    System.out.print("\"" + lvl + "\"");
    System.exit(1);
   }

    double minPay = (bal * 0.03);
    double totalMinPay = (minPay + lateFee) + (intrst * bal);

    System.out.println("Card Balance: $" +  bal);
    System.out.println("Minimum payment to principle (3% of principle): $" + (minPay));
    System.out.println("Minimum total payment (payment and fees): $" + totalMinPay);

Answer 1

您可以使用 printf 方法，如下所示:

 System.out.printf("%.2f", bal);

简而言之，%.2f 语法告诉 Java 返回您的变量 (bal)，保留 2 位小数。