检查对象是否在我创建的列表中[重复]

Question

我正在制作一个注册多个参数的代码，然后检查这些参数是否已经在列表中，例如，我想检查一个电子邮件是否在这个列表中，我该怎么做检查？

List<Professional> lprofessional = new List<Professional>();

public int role_id = 1;
public string First_name { get; set; }
public string Last_name { get; set; }
public string Email { get; set; }
public string Phone { get; set; }
public string Description { get; set; }

public Professional(int role_id, string firstname, string lastname, string email, string phone, string description) {
    this.First_name = firstname;
    this.Last_name = lastname;
    this.Email = email;
    this.Phone = phone;
    this.Description = description;
}

public void Create()
{
    Professional pro = new Professional(role_id, First_name, Last_name, Email, Phone, Description);
    if (lprofessional.Contains(email)//Here is the check maybe...
    {
        lprofessional.Add(pro);
        role_id++;
    }
}

Answer 1

if (lprofessional.Any(p => p.Email == email))
{
    // already in the list
}
else
{
    // not yet in the list
}

或者：

var p = lprofessional.FirstOrDefault(p => p.Email == email);
if (p is object)
{
    //already in the list, and you can use "p" to see or change other properties
}
else
{
    // not in the list
}

我知道还有使用模式匹配的更新选项可以用更少的代码做到这一点，但我还没有将模式匹配整合到我自己的工作流程中。

Answer 2

var email = "test@test.com";
var listElement = lprofessional.Where(x=> x.Email.Equals(email)).FirstOrDefault();
    if(listElement != null)
    {
    //some code
     }

或

var email = "test@test.com";
var result = lprofessional.Any(x => x.Email.Equals(email));
if( result) 
{
//some code here
}