Test
create a new person class
public class Person
{
public Person(string name,int id)
{
Name = name;
Id = id;
}
public string Name { get; set; }
public int Id { get; set; }
}
Initialize a million pieces of data in the list, and then use each method to determine whether Xiaoming is in the list. The code is as follows
static void Main(string[] args)
{
List<Person> persons = new List<Person>();
//Initialize persons data
for (int i = 0; i < 1000000; i++)
{
Person person = new Person("My" + i,i);
persons.Add(person);
}
Person xiaoming=new Person("My999999", 999999);
//The following three methods are used to determine whether persons contain xiaoming
Stopwatch watch = new Stopwatch();
watch.Start();
bool a = persons.Contains(xiaoming);
watch.Stop();
Stopwatch watch1 = new Stopwatch();
watch1.Start();
bool b = persons.Exists(x=>x.Id==xiaoming.Id);
watch1.Stop();
Stopwatch watch2 = new Stopwatch();
watch2.Start();
bool c = persons.Where(x=>x.Id==xiaoming.Id).Any();
watch2.Stop();
Stopwatch watch3 = new Stopwatch();
watch3.Start();
bool d = persons.Any(x => x.Id == xiaoming.Id);
watch3.Stop();
Console.WriteLine("Contains time:" + watch.Elapsed.TotalMilliseconds);
Console.WriteLine("Exists time:" + watch1.Elapsed.TotalMilliseconds);
Console.WriteLine("Where time:" + watch2.Elapsed.TotalMilliseconds);
Console.WriteLine("Any time:" + watch3.Elapsed.TotalMilliseconds);
Console.ReadLine();
}
The execution result is shown in the figure below
Conclusion
it can be seen from the figure above that the performance ranking is
Contains > Exists > Where > Any
Note:
no query conditions are allowed in contains
This article about the detailed explanation of C # list contains, exists, any, where performance comparison is introduced here. For more related C # contains, exists, any, where content, please search the previous articles of C # tutorial script home or continue to browse the following related articles. I hope you can support more in the future