Combine for和while循環（Java）

Question

我是新來的Java，我試圖讓一個程序，允許用戶輸入100個數字，如果用戶寫'0'，那麼該程序是假設打印最小，最大，總和和所有數字。我得到了所有的工作，但不是退出並打印所有。我的老師說了一些關於使用while循環的內容，但是當你有一個for循環時怎麼可能呢？

問候

public static void main(String[] args) { 
    int[] list = new int[100]; 
    int min = 0; 
    int max = 0; 
    int sum = 0; 
    boolean first = true; 

    Scanner scan = new Scanner(System.in); 
    while(list[i] != 0) { 
     for (int i = 0; i < list.length; i++) { 

      System.out.print("Enter number (0 to exit) " + (1 + i) + ":"); 
      list[i] = scan.nextInt(); 
     } 

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

      if (first == true) { 

      min = list[i]; 
      first = false; 
     } 

     if (list[i] < min) { 

      min = list[i]; 
     } 

     else if (list[i] > max) { 

      max = list[i]; 
     } 

     sum = list[i] + sum; 

    } 

    if (list[i] == 0) { 

    System.out.print("Numbers are: " + list[0] + ", "); 

    for (int i = 1; i < list.length; i++) 

    System.out.print(list[i] + ", "); 
    System.out.println(); 

    System.out.println("Smallest number is: " + min); 
    System.out.println("Largest numeber is: " + min); 
    System.out.println("Sum is: " + sum); 
    } 
    } 
} 

} 

Answer 1

下面是方法的主體，它會做你所問過的。我沒有使用while循環（但實際上，for循環是內部的一種while循環）。

int size = 100; // Set the number of numbers to input. 
int[] list = new int[size]; // Create an array with 'size' elements. 
int min = Integer.MAX_VALUE; // Set the highest possible integer as start value. 
int max = 0; // Set the minimum to zero, assuming that the user won't input negative numbers. 
int sum = 0; // Initialize the sum of the numbers in the list. 

Scanner scan = new Scanner(System.in); 

for (int i = 0; i < size; i++) { // Run 'size' times the process of inputting a number. 
    System.out.print("Enter number (0 to exit) " + (i + 1) + ": "); 
    int number = scan.nextInt(); 
    if (number == 0) { // Quit program if input equals '0' 
     System.out.println("Exiting..."); 
     break; 
    } 
    list[i] = number; // Add the current number to the list 
    sum += number; // Add the number to the total 
    if (number < min) { // If the number is smaller than the previous one, set this number as the smallest 
     min = number; 
    } 
    if (number > max) { // If the number is greater than the previous smallest number, set this number as the greatest 
     max = number; 
    } 
} 

// Output all numbers in the list 
for (int i = 0; i < list.length; i++) { 
    if (list[i] != 0) { 
     System.out.print((i == 0 ? "" : ", ") + list[i]); 
    } 
} 

// You see the snippet (i == 0 ? "" : ", ") 
// That is a shorthand if-else statement: 
// If i equals 0, then "" (empty string), else ", " (comma and space). 
// The statement 
//  System.out.print((i == 0 ? "" : ", ") + list[i]) 
// is the same as 
//  if (i == 0) { 
//   System.out.println("") + list[i]; 
//  } 
//  else { 
//   System.out.println(", ") + list[i]; 
//  } 

System.out.println("Smallest number is: " + min); 
System.out.println("Largest numeber is: " + max); 
System.out.println("Sum is: " + sum); 

Answer 2

你糊塗代碼。更好地使用這樣的模式：

while (true) { 
    // read next 
    if (input == 0) 
     break; 
} 

Answer 3

你只需要一個while循環來做到這一點，另外一個for循環只是，如果你想打印數組：

Scanner scan = new Scanner(System.in); 
int i = 0; 
int sum = 0; 
int maxValue = Integer.MIN_VALUE; 
int[] history = new int[100]; 
System.out.println("INPUT:"); 
int option = scan.nextInt(); 
while (option != 0 && i <= 100) 
{ 
    if (option > maxValue) 
     maxValue=option; 
    sum += option; 
    history[i] = option; 
    option = scan.nextInt(); 
    i++; 
} 
System.out.println("OUTPUT: \n" + "SUM: " + sum + "\n MAX VALUE: " + maxValue); 
for (int x : history) 
    System.out.print(x + "");