Code►C#

C# 資料分群

在這邊主要介紹List的分群，如有以下的五筆資料

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["00001","00002","00003","00004","00005"]

這時想要以2來群分，變成下方結果

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[["00001","00002"],["00003","00004"],["00005"]]

程式碼:

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using System;
using System.Linq;
using System.Collections.Generic;
using System.Text.Json;

namespace ListGroupBy
{
    internal class Program
    {
        static void Main(string[] args)
        {
            var numbers = new List<string>
            {
                "00001","00002","00003","00004","00005"
            };

            var numberGroup = numbers
                .Select((number, index) => new { number, index })
                .GroupBy(g => g.index / 2, i => i.number)
                .ToList();

            //It will iterate through each groups
            foreach (var group in numberGroup)
            {
                Console.WriteLine($"{group.Key} ,  count: {group.Count()}");
                //Iterate through each number of a group
                foreach (var number in group)
                    Console.WriteLine($"  number : {number}");
            }
        }
    }
}

output:

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0 ,  count: 2
  number : 00001
  number : 00002
1 ,  count: 2
  number : 00003
  number : 00004
2 ,  count: 1
  number : 00005