如何爲多個整數創建1個for循環？

Question

有沒有辦法只使用一個循環與多個整數？目前我只寫了int num0的代碼。但有沒有辦法讓同一代碼中的num1，num2，num3的其餘部分？我之所以要求這樣做的原因是因爲我不像程序員那樣經驗豐富，我想知道你們是否知道是否有解決方案。 （請原諒我的語法錯誤）

public void exercise1c() { 
     int num0, num1, num2, num3; 

     num0 = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 
     num1 = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 
     num2 = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 
     num3 = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 

     for (int i = 0; i <= num0; i++) { 
     if (num0 <= 0) { 
      System.out.println("Number "+ num0 + " is negative."); 
      break; 
     } 
     } 
     if (num0 >= 0) { 
     System.out.println(num0 + " is a integer."); 
     } 
     if (num0 == 0){ 
     System.out.println(num0 + " is zero."); 
     } 
    } 

Answer 1

加num0, num1, num2, num3到List或array，然後你就可以使用單for環

如：與int[]

int[] num = new int[4]; 
num[0] = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 
num[1] = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 
num[2] = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 
num[3] = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 

for (int i = 0; i < num.length; i++) { 
    if (num[i] < 0) { 
     System.out.println("Number " + num[i] + " is negative."); 
     break; 
    } 
    if (num[i] > 0) { 
     System.out.println(num[i] + " is a integer."); 
    } 
    if (num[i] == 0) { 
     System.out.println(num[i] + " is zero."); 
    } 
} 

如何使用List

如這樣做：

List<Integer> numList = new ArrayList<>(); 
    numList.add(Integer.parseInt(JOptionPane.showInputDialog("Write a number."))); 
    numList.add(Integer.parseInt(JOptionPane.showInputDialog("Write a number."))); 
    numList.add(Integer.parseInt(JOptionPane.showInputDialog("Write a number."))); 
    numList.add(Integer.parseInt(JOptionPane.showInputDialog("Write a number."))); 

    for (Integer i :numList) { 
     if (i < 0) { 
      System.out.println("Number " + i + " is negative."); 
      break; 
     } 
     if (i > 0) { 
      System.out.println(i + " is a integer."); 
     } 
     if (i == 0) { 
      System.out.println(i + " is zero."); 
     } 
    } 

Answer 2

使用的array：

int[] num = new int[4]; 

num[0] = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 
num[1] = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 
num[2] = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 
num[3] = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 

for(int i = 0; i<num.length; i++) { 
    int currentInteger = num[i]; 

    //other code here... 
} 

Answer 3

首先，這些對象NUM＃不是數組，但原語，如果它們是整數。 如果三個陣列長度相同，答案是肯定的！

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

但如果你在一個數組，尋找迭代的快捷方式

for (int i : numArray) 
    System.out.println("The number is: " + i); 

Answer 4

，你可以這樣做：

int num[]=new int[4]; 

    for(int i=0;i<4;i++){ 
     num[i] = Integer.parseInt(JOptionPane.showInputDialog("Write a number.")); 
    } 

    // Do something 

Answer 5

也許你的意思是這樣的：

static final int N = 4; // <-- the number of integers you have. 
public void exercise1c() { 
    int num[] = new int [4]; 
    for (i = 0; i < N; i++) { 
     num[i] = Integer.ParseInt(JOptionPane.showInputDialog("Write a number.")); 
     // you need here some means to get the number into num[i]. 
    } /* for */ 
    for (i = 0; i < N; i++) { 
     if (num[i] < 0) { // < 0 for negative number. 0 is not negative. 
      System.out.println("Number " + num[i] + " is negative."); 
      // break; // don't know what you pretend here. 
     } else if (num[i] > 0) { 
      System.out.println("Number " + num[i] + " is positive."); 
     } else { 
      System.out.println("Number " + num[i] + " is zero."); 
     } /* if */ 
    } /* for */ 
} /* exercise1c() */