java - 数组、 double 、IF/Else

Question

我想使用数字数组编写代码，显然不是字符串，并且它们需要是 double 的。我编写代码的方式是我知道的唯一可行的方式。也许我把它弄得太复杂了，数组会让它变得简单我不知道。我对编程很陌生，几天之内就是新的。请帮忙。

需要的是:编写一个代码，对 10 个数字的输入进行平均，并显示平均值以及它们是否通过。如果 < 50 失败，否则 > 50 通过。

我们必须使用一个数组，我们需要使用JOptionPane.showMessageDialog。，数字需要是 double 并四舍五入到两位小数。

我声明了 double，但如果输入十进制数，则会出现错误。如果我只是按原样运行代码，它会让我输入 10 个数字，对它们求平均值，然后告诉我是否通过或失败。当谈到使用其他因素时，我只是迷失了方向。谢谢

工作代码如下:

package avgpassorfail;


import javax.swing.JOptionPane;

public class Avgpassorfail {

public static void main(String[] args) {

   String firstNumber, 
     secondNumber, 
     thirdNumber,
     fourthNumber,
     fifthNumber,
     sixthNumber,
     seventhNumber,
     eighthNumber,
     ninethNumber,
     tenthNumber;

double number1,     
number2,
number3,
number4,
number5,
number6,
number7,
number8,
number9,
number10,
sum;                

    firstNumber =
    JOptionPane.showInputDialog ( "Enter 1st Grade" );

    secondNumber =
    JOptionPane.showInputDialog ( "Enter 2nd Grade" );

    thirdNumber =
    JOptionPane.showInputDialog ( "Enter 3rd Grade" );

    fourthNumber =
    JOptionPane.showInputDialog ( "Enter 4th Grade" );

    fifthNumber =
    JOptionPane.showInputDialog ( "Enter 5th Grade" );

    sixthNumber =
    JOptionPane.showInputDialog ( "Enter 6th Grade" );

    seventhNumber =
    JOptionPane.showInputDialog ( "Enter 7th Grade" );

    eighthNumber =
    JOptionPane.showInputDialog ( "Enter 8th Grade" );

     ninethNumber =
     JOptionPane.showInputDialog ( "Enter 9th Grade" );

     tenthNumber =
     JOptionPane.showInputDialog ( "Enter 10th Grade" );


number1 = Integer.parseInt ( firstNumber);
number2 = Integer.parseInt ( secondNumber);
number3 = Integer.parseInt ( thirdNumber);
number4 = Integer.parseInt ( fourthNumber);
number5 = Integer.parseInt ( fifthNumber);
number6 = Integer.parseInt ( sixthNumber);
number7 = Integer.parseInt ( seventhNumber);
number8 = Integer.parseInt ( eighthNumber);
number9 = Integer.parseInt ( ninethNumber);
number10 = Integer.parseInt ( tenthNumber);


sum = (number1 + number2 + number3 + number4 + number5 + number6 + number7 + number8 +number9 + number10)/10;


JOptionPane.showMessageDialog (
null, "The Average is " + sum, "Results",
JOptionPane.PLAIN_MESSAGE);

if (sum < 50){
JOptionPane.showMessageDialog (
null, "Fail", "Results",
JOptionPane.PLAIN_MESSAGE);

}else{
JOptionPane.showMessageDialog (
null, "Pass", "Results",
JOptionPane.PLAIN_MESSAGE);
} 
System.exit ( 0 ); 
}
} 

Answer 1

哇哦，这是很多的重复。您可能应该使用循环来清理它，例如:

double sum = 0; // initialize variable for sum of all the numbers
for (int i = 1; i <= 10; i ++) { // go from 1 to 10
    String strNum = JOptionPane.showInputDialog("Enter grade #" + i); // prompt for input
    double dNum = Double.parseDouble(strNum); // convert to double
    sum += dNum; // add to sum
}
double avg = sum / 10; // now get the average