How do I override the Equals method in C#?

How do I override the Equals method in C#?

To override the Equals method in C#, you need to provide a custom implementation in your class. Here's a basic example:

public class MyClass
{
    public int Id { get; set; }
    public string Name { get; set; }

    public override bool Equals(object obj)
    {
        if (obj is MyClass other)
        {
            return this.Id == other.Id && this.Name == other.Name;
        }
        return false;
    }

    public override int GetHashCode()
    {
        return HashCode.Combine(Id, Name);
    }
}

Why is it important to override GetHashCode when overriding Equals?

It's important to override GetHashCode because if two objects are considered equal (i.e., their Equals method returns true), they must return the same hash code. This is crucial for the correct functioning of hash-based collections like HashSet and Dictionary.

Can you give an example of using these methods in a collection?

Sure! Here's how you can use your class in a HashSet:

HashSet<MyClass> mySet = new HashSet<MyClass>();
mySet.Add(new MyClass { Id = 1, Name = "Test" });

bool contains = mySet.Contains(new MyClass { Id = 1, Name = "Test" }); // This will return true due to overridden methods.