如何访问部分初始化数组中不为0的元素?
本文关键字:元素 数组 初始化 何访问 访问 | 更新日期: 2023-09-27 18:15:44
我想将用户为数组输入的所有值相乘。问题是,如果使用的数组元素少于50个,那么结果总是0。是否有一种方法可以只访问用户输入的元素?
static void Main(string[] args)
{
const int SIZE = 50;
int[] array = new int[SIZE];
int index = 0;
int aScore = 0;
do
{
Console.WriteLine("Enter a value for the array for position {0} (or 0 to stop):", (index + 1));
aScore = int.Parse(Console.ReadLine());
if(aScore >= 0)
{
array[index++] = aScore;
}
}while (aScore != 0 && index < SIZE);
Console.WriteLine("The product of the array is: {0}", SumArray(array));
Console.ReadLine();
}
static int SumArray(int[] array)
{
int product = 1;
for (int i = 0; i < array.Length; i++)
{
product *= array[i];
}
return product;
}
var values = array.Where(x => x != 0).ToArray();
确保你有using System.Linq;
正如Tim上面所说的,使用List<int>
将是解决这个问题的首选方法。如果使用List<int>
,则可以使用LINQ聚合函数,如下所示
var ints = new List<int> {1, 2, 3, 4, 5};
var product = ints.Aggregate((total, nextNum) => total * nextNum); // product = 120
编辑这里有一个完整的例子来说明我是怎么做的
private static void Main()
{
const int maxScores = 50;
int index = 0;
int nextScore = 0;
var scores = new List<int>();
do
{
Console.WriteLine("Enter a value for the array for position {0} (or 0 to stop):", ++index);
nextScore = int.Parse(Console.ReadLine());
if (nextScore > 0)
scores.Add(nextScore);
} while (nextScore != 0 && index < maxScores);
Console.WriteLine("The product of the scores is : {0}",
scores.Aggregate((total, next) => total * next));
Console.ReadLine();
}
乘前检查是否为0:
if (array[i] != 0)
product *= array[i]
如果您想要"求和"数组,操作应该是+=
你的方法
static int SumArray(int[] array)
{
int product = 1;
for (int i = 0; i < array.Length; i++)
{
product *= array[i];
}
return product;
}
应该像这样
static int SumArray(int[] array)
{
int product = 1;
for (int i = 0; i < array.Length; i++)
{
if (array[i] != 0)
{
product *= array[i];
}
}
return product;
}
和
do
{
Console.WriteLine("Enter a value for the array for position {0} (or 0 to stop):", (index + 1));
aScore = int.Parse(Console.ReadLine());
if(aScore >= 0)
{
array[index++] = aScore;
}
}while (aScore != 0 && index < SIZE);
这部分对于实现您的目标来说不是一个好的实践,因为您也将值为0的记录放入了数组中。你可以用
代替它if(score> 0)
,但我建议您使用List而不是数组,这样您就不会遇到额外的不必要元素的问题。
你可以完全省略你的SumArray()
方法,只写:
int product = array
.Where( n => n != 0 )
.Aggregate( 1 , (m,n) => m*n )
;
Console.WriteLine( "The product of the array is: {0}" ,
) ;
你可以使用List<int>
(这实际上只是一个可调长度数组在掩护下),不用担心它:
static void Main( string[] args )
{
List<int> scores = new List<int>() ;
while ( true )
{
Console.WriteLine( "Enter a value for the array for position {0} (or 0 to stop):" ,
1+scores.Count
) ;
int score = int.Parse( Console.ReadLine() ) ;
if ( score == 0 ) break ;
values.Add(score);
}
int product = scores.Aggregate( 1 , (m,n) => m*n ) ;
Console.WriteLine( "The product of the array is: {0}" , product ) ;
return ;
}
或者你可以完全不维护收藏,只是把东西打包:
static void Main( string[] args )
{
int sum = 0 ;
int n = 0 ;
int product = 1 ;
while ( true )
{
Console.WriteLine( "Enter a value for the array for position {0} (or 0 to stop):" ,
1+scores.Count
) ;
int score = int.Parse( Console.ReadLine() ) ;
if ( score == 0 ) break ;
sum += score ;
product *= score ;
n++ ;
}
Console.WriteLine( "The product of the array is: {0}" , product ) ;
Console.WriteLine( "The sum of {0} scores is {1}" , n , sum ) ;
Console.WriteLine( "The mean score is {0}" , (double)sum/(double)n ) ;
return ;
}
如果在for循环中测试if (array[i] > 0)
,则可以进行多次测试。例如,输入三个数字,则该条件将测试47次。
所以,如果你发现一个0,最好打破循环。
<!-- language: lang-cs -->
static int SumArray(int[] array)
{
int product = 1;
for (int i = 0; i < array.Length; i++)
{
if (array[i] == 0) break;
product *= array[i];
}
return product;
}