30秒学会 C# 片段 – FindFirstBy

Returns the first element in a collection that matches the given predicate function, match.

Use IEnumerable.Where() to filter out all values in data for which match returns false.
Use IEnumerable.First() to return only the first matching element.

代码实现

using System.Collections.Generic;
using System.Linq;

public static partial class _30s 
{
  public static T FindFirstBy<T>(IEnumerable<T> data, Predicate<T> match)
  {
    return data.Where(i => match(i)).First();
  }
}

使用样例

int[] nums = {1, 2, 4, 5, 2, 2, 4};

_30s.FindFirstBy(nums, x => x % 2 == 0); // 2