从数组 c# 输出一定数量的元素

Question

How could I go about, lets say for example outputting 3 elements of an array per line on the console? And doing this for the whole array? Is there anything like the Java Scanner that could help me?

Answer 1

One way to do this would be with a for loop. You could use something like the following:

// input already defined as array
for (int i = 0; i < input.Length; i += 3) {
    Console.WriteLine(input[i] + ' ' + input[i + 1] + ' ' + input [i + 2]);
}

This would require that your array had a length that was a multiple of three; if this wasn't the case, you'd need to add some sort of logic checking that input[i + 1] and input[i + 2] existed within the array.

A possible, albeit somewhat verbose solution, would be like so:

for (int i = 0; i < input.Length; i += 3) {
  if (i + 2 >= input.length) {
      Console.WriteLine(input[i] + ' ' + input[i + 1] + ' ' + input[i + 2]);
  } else if (input[i + 1] >= input.length) {
      Console.WriteLine(input[i] + ' ' + input[i + 1]);
  } else {
      Console.WriteLine(input[i]);
  }
}

Answer 2

Linq solution:

  int[] data = Enumerable.Range(1, 20).ToArray();

  int groupSize = 3;

  var result = Enumerable
    .Range(0, data.Length / groupSize + 
             (data.Length % groupSize == 0 ? 0 : 1))
    .Select(index => data.Skip(index * groupSize).Take(groupSize))
    .Select(items => string.Join(", ", items));

  Console.Write(string.Join(Environment.NewLine, result));

Output:

1, 2, 3
4, 5, 6
7, 8, 9
10, 11, 12
13, 14, 15
16, 17, 18
19, 20

Answer 3

Let arrayElements be the input, then you can group them into chunks of specified size and collect values from each groups and display it:

List<int> arrayElements = new List<int>() { 1,5,2,3,6,4,87,96,54,5,4,5,6,2,5,9,5,5,5,6,2,45,6};

int chunkSize = 3;
var results = arrayElements.Select((x, i) => new { Key = i / chunkSize , Value = x })
                           .GroupBy(x => x.Key, x => x.Value)
                           .Select(x=>String.Join("  ",x.ToList()))
                           .ToList();

foreach (string chunk in results)
{
    Console.WriteLine(chunk);
}

Working Example

Answer 4

You can do some thing like this. It will print elements in a single line and will go to new line after printing three elements in a row.

    for(int i=0; i<arr.Length; ++i) {
        Console.Write(arr[i]+" ");

        if((i+1)%3==0){
            Console.WriteLine("");      
        }
    }