Question

我正在制定一个信用卡计划，告诉您应该先付清哪张卡。所有卡都是从用户读入的。我的问题似乎是我无法找到一种方法来显示利率最高的卡。

我已经设置了一个名为findHighestRate的方法，它的工作（正如您所猜测的）是查看数组并找到用户输入的最高利率。现在我相信代码的一部分是正确的，但我已经尝试了无数次通过我的显示方法显示最高的一个（显示图表中的所有用户输入），但每次都显得很短。

public static void header ()
{
    System.out.printf("%9s %22s %24s %29s" , "Card" , "Rate of Interest" , "Current Amount Owed", "Amount owed in One Year");
    System.out.println();
    System.out.print("============================");
    System.out.print("=================================================================");
    System.out.print("=====");
}

public static void display (String card [], double rOI [], double current [], double owed1yr [], int i)
{

    System.out.printf("\n%11s %14.2f %25.2f %25.2f" , card[i], rOI[i], current[i], owed1yr[i]);
}

public static String getString (String s)
{
    Scanner keyIn = new Scanner (System.in);
    //prompt

    System.out.print(s+": ");
    return keyIn.nextLine().trim();
}

public static int findHighestRate(double interestRate [], int index )
{
    double max = 0;
    index = -1;
    for (int i = 0; i < interestRate.length; i++)
        if (interestRate[i] > max){
            max = interestRate[i];
            index = i;
    }
    return index;
}

public static double getDouble( String s)

{
    Scanner stdIn = new Scanner (System.in);
    // Prompt the user for the string needed
    System.out.print(s+": ");
    return stdIn.nextDouble();

}

public static void main (String [] args)
{
    //bringing arrays to life.
    String [] c = new String [4];   
    double [] rateOfInterest = new double [4];
    double [] currentAmountOwed = new double [4];
    double [] yr1Owed = new double [4];

    int index =0;
    intro();
    System.out.println("Please enter the name of the card, interest rate, and amount owed");
    for (int i = 0; i <c.length; i++){
        System.out.println();

        c[i] = getString ("Card");
        rateOfInterest [i] = getDouble("Rate of interest");
        currentAmountOwed [i] = getDouble ("Amount Owed");

    }
    System.out.println();

    for (int i =0 ; i < c.length; i++){
        yr1Owed[i] = ((rateOfInterest[i] * currentAmountOwed[i]   / 100) + currentAmountOwed[i]);
    }

    header();

    for ( int i = 0; i <c.length; i++)
    {
        display(c, rateOfInterest, currentAmountOwed,yr1Owed, i  );

    }
    System.out.println();
    System.out.println();

    System.out.println("Seach for the highest rate of interest.. Pay this off first");
    System.out.println();
    header();

    for ( int i = 0; i <c.length; i++)
    {

        FIND HIGHEST RATE METHOD HERE

    }

    //highest rate part of code not included..... did not complete.
}

}

Answer 1

你的方法

// I've removed the index parameter as it makes no sense
public static int findHighestRate(double interestRate [])

的返回类型为int。因此，您必须使方法返回一个值。如果它返回一个值，您可以将该值赋给变量或将其用作另一个方法的参数。

例如

int index = findHighestRate(someDoubleArray);

然后，您可以使用该变量的值来访问数组中的元素

double highestRate = someDoubleArray[index];

然后您可以打印出该值

System.out.println(highestRate);

如何在Java中显示数组的某个元素？

1 个答案: