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java - 如何乘以用户输入的数组？

问题描述

我正在制作一个程序，要求用户输入数组的长度，然后询问数组的元素。我的问题是如何将这些元素相乘？例如：数组的长度是多少？：4 数组的元素是什么？：3 6 4 7 {3 6 4 7} 的乘积是 504。到目前为止，这是我的代码：

     Scanner s = new Scanner(System.in);
     System.out.println("The length of your array is: ");
     int length = s.nextInt();
     int [] myArray = new int [length];
     System.out.println("The elements of your array are: ");

     for(int i=0; i<length; i++ ) {
        myArray[i] = s.nextInt();
     }

     System.out.printf("The multiplication of {%s} is ",Arrays.toString(myArray));

  }
}

任何帮助，将不胜感激。

标签： javaarraysjava.util.scanner

解决方案

Scanner s = new Scanner(System.in);
    System.out.println("The length of your array is: ");
    int length = s.nextInt();    
    System.out.println("The elements of your array are: ");
long product = 1;
    for (int i = 0; i < length; i++) {
      product *= s.nextInt();
    }

    System.out.printf("The multiplication of {%s} is ", product);

稍作调整更新了您的代码

交替使用 lambda：

Scanner s = new Scanner(System.in);
List<Integer> numbers = new ArrayList();
System.out.println("The length of your array is: ");
int length = s.nextInt();    
System.out.println("The elements of your array are: ");


numbers = IntStream.range(0, length)
.mapToObj(i -> Integer.valueOf(s.nextInt()))
.collect(Collectors.toList());

System.out.printf("The multiplication of {%s} is {%s}",numbers, 
numbers.parallelStream()
.reduce(1, 
(number, product) -> product * number));

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