使用 JOptionPane 在 Java 中執行 while 循環

Question

我試圖構建一個程序來確定它是負數還是正數，到目前為止它很好，但似乎我的代碼沒有讀取負數，只有正數，我找不到它有什么問題。

import javax.swing.JOptionPane;

public class EYYY {

    public static void main(String[] args) {    
        int positive=0;
        int negative=0;
        int num=0;
        int loop = 1;

        while(loop<=5){


            Integer.parseInt(JOptionPane.showInputDialog("Enter a number: "));
            if(num<0)
                negative++;

            if(num>=0)
                positive++;
            loop++;
        }

         JOptionPane.showMessageDialog(null,"Negative numbers in the program: " + negative + "\nPositive numbers in the program: " + positive);
      
    }
}

Answer 1

num=0; 導致num值始終為零和正數，但您需要在while-loop的每次迭代中將JOptionPane的輸入值存儲在num變量中，以檢查新輸入值的負數或正數：

num = Integer.parseInt(JOptionPane.showInputDialog("Enter a number: "));

完整代碼：

int positive = 0;
int negative = 0;
int num = 0;
int loop = 1;

while (loop <= 5) {

    num = Integer.parseInt(JOptionPane.showInputDialog("Enter a number: "));
    if (num < 0)
        negative++;

    if (num >= 0)
        positive++;
    loop++;
}

JOptionPane.showMessageDialog(null,
        "Negative numbers in the program: " + negative + "\nPositive numbers in the program: " + positive);