Linq Count Expression

Question

假设以下Employee类（是的，我知道我不应公开公开列表，但这只是一个例子）：

class Employee
{
    public string Name {get; set;}
    public List<string> Skills {get; set;}
}

技能只是员工的技能列表，例如“编程”，“客户服务”等。

现在假设我有一个List<Employee> CurrentEmployees，我还有另一名员工，Employee NewHire不在CurrentEmployees列表中。

我的目标是使用lambda表达式来计算CurrentEmployees中至少有一项NewHire技能的员工的数量。例如，如果CurrentEmployees包含一名Skills{'Programming', 'Troubleshooting'}员工，另一名员工Skills{'Accounting','Finance'}，而NewHire有Skills{'Programming','Networking'}，我希望表达式返回1，因为列表中的第一名员工也将“编程”作为一种技能......这可能吗？

感谢您的帮助。

Answer 1

var currentEmployees = new List<Employee>
{
    new Employee { Skills = new List<string> { "Programming", "Troubleshooting" } },
    new Employee { Skills = new List<string> { "Accounting", "Finance" } },
};

var newHire = new Employee { Skills = new List<string> { "Programming", "Networking" } };

var count = currentEmployees.Count(e => e.Skills.Any(newHire.Skills.Contains));
// count == 1

Answer 2

 currentEmployees.Count(ce =>
               ce.Skills.Intersect(newHire.Skills).Any())

Answer 3

如果表现很重要，我会使用HashSet<string>：

var newHireSkills = new HashSet<string>(newHire.Skills);

var count = currentEmployees.Count(e => e.Skills.Any(s => newHireSkills.Contains(s)));