Question

只要条件sumaA> sumaB被满足，我就想运行“ while”循环。如何显示迭代次数以及sumaA和sumaB的当前值？

import java.util.*;

class Sum {
    public static void main(String[] args) {

        int sumaA = 1000;
        int sumaB = 0;

        Random rand = new Random();
        int n = rand.nextInt(9);
        int g = rand.nextInt(49);{
            System.out.println("Random N= "+ n);

            sumaA += n;
            System.out.println("sumaA: "+sumaA);
            System.out.println();

            System.out.println("Random N= "+ g);
            sumaB += g;
            System.out.println("sumaB: "+sumaB);

            while (sumaA>sumaB);

            }
        System.out.println("loop runs numbers");
        System.out.println("value sumaA" + sumaA + "value sumaB " + sumaB);

        }
    }

Answer 1

您必须更正while循环，因为在当前状态下，它什么也不会做。

这是对您的代码的更正，基本上可以正常工作（我不知道所需的输出，但是看起来还可以）：

public static void main(String[] args) {

    int sumaA = 1000;
    int sumaB = 0;

    Random rand = new Random();
    int n = rand.nextInt(9);
    int g = rand.nextInt(49);

    int runCounter = 0;

    while (sumaA > sumaB) {
        runCounter++;
        System.out.println("Loop run number " + runCounter);
        System.out.println("Random N = " + n);

        sumaA += n;
        System.out.println("sumaA: " + sumaA);
        System.out.println();

        System.out.println("Random N= " + g);
        sumaB += g;
        System.out.println("sumaB: " + sumaB);
    }

    System.out.println("loop ran " + runCounter + " times");
    System.out.println("value sumaA" + sumaA + "value sumaB " + sumaB);
}

请查看循环的外观。每次循环运行将要执行的所有内容都必须在循环体内（花括号）。

Answer 2

您必须正确构造while循环，并获取局部变量counter并将其初始化为0。在迭代时，将counter变量加+1。请考虑以下代码：

public static void main( String[] args )
   {
      int sumaA = 1000;
      int sumaB = 0;
      int counter = 0;
      Random rand = new Random();
      int n = rand.nextInt( 9 );
      int g = rand.nextInt( 49 );
      while ( sumaA > sumaB )
      {
         System.out.println( "Random N= " + n );

         sumaA += n;
         System.out.println( "sumaA: " + sumaA );
         System.out.println();

         System.out.println( "Random N= " + g );
         sumaB += g;
         System.out.println( "sumaB: " + sumaB );
         counter++;
      }
      System.out.println( "loop runs numbers " + counter );
      System.out.println( "value sumaA " + sumaA + "value sumaB " + sumaB );
   }

Answer 3

while循环在小节内的代码，直到括号内的条件为假。例如，这段代码：

int i = 0;
loops = 0
while(i < 6){
  loops++;
  System.out.println("loop runs numbers"+loops);
  i+=2;
  System.out.println("i: "+i);
}

输出：

循环运行数字1

i：2

循环运行数字2

i：4

循环运行数字3

i：6

然后停止，因为我不小于6。

现在代码的问题是，在while括号内没有任何指令，因此括号内的条件以true开头，永远不会为false，因为您没有在循环内更改任何内容。您应该做的是将代码移到while括号内，如果希望计算循环运行次数，则添加一个“ loops”变量。最终代码应如下所示：


import java.util.*;

class Sum {
    public static void main(String[] args) {
    int sumaA = 1000;
    int sumaB = 0;
    int loops = 0;

    while (sumaA>sumaB){
      Random rand = new Random();
      int n = rand.nextInt(9);
      int g = rand.nextInt(49);{
      System.out.println("Random N= "+ n);
      sumaA += n;
      System.out.println("sumaA: "+sumaA);
      System.out.println();
      System.out.println("Random N= "+ g);
      sumaB += g;
      System.out.println("sumaB: "+sumaB);
      loops++;
      System.out.println("loop runs numbers"+loops);
      System.out.println("value sumaA" + sumaA + "value sumaB " + sumaB);
    }
  }
}

Answer 4

    do {  
    int n = rand.nextInt(9);
    int g = rand.nextInt(49);

        System.out.println("Random N= "+ n);

        sumaA += n;
        System.out.println("sumaA: "+sumaA);
        System.out.println();

        System.out.println("Random N= "+ g);
        sumaB += g;
        System.out.println("sumaB: "+sumaB);
        System.out.println("loop runs numbers");
        System.out.println("value sumaA" + sumaA + "value sumaB " + sumaB);
        }  while (sumaA>sumaB);

    }

你好，这是你想做什么吗？

while循环如何显示循环运行次数

4 个答案: