Learn how to combine two arrays without duplicate values in C# using the Union() method.
Example: Combine String Arrays
string[] animals = { "Cat", "Alligator", "Fox", "Donkey", "Cat" };
string[] birds = { "Sparrow", "Peacock", "Dove", "Crow" };
var all = animals.Union(birds).ToArray();
In the same way, use the Union() method with the number array.
Example:
int[] num1 = { 1, 2, 3, 4, 3, 55, 23, 2 };
int[] num2 = { 55, 23, 45, 50, 80 };
var all = num1.Union(num2).ToArray();
If an array contains objects of a custom class, then you need to implement IEquatable<T> or IEqualityComparer<T>, as shown below.
Example: Implement IEquatable
class Person : IEquatable<Person>
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public bool Equals(Person other)
{
return FirstName.Equals(other.FirstName) && LastName.Equals(other.LastName);
}
public override int GetHashCode()
{
return Id.GetHashCode() ^ (FirstName == null ? 0 : FirstName.GetHashCode()) ^ (LastName == null ? 0 : LastName.GetHashCode());
}
}
Now, you can use the Union() method, as shown below.
Example: Combine Object Arrays
Person[] people1 = {
new Person(){ FirstName="Steve", LastName="Jobs"},
new Person(){ FirstName="Bill", LastName="Gates"},
new Person(){ FirstName="Steve", LastName="Jobs"},
new Person(){ FirstName="Lary", LastName="Page"}
};
Person[] people2 = {
new Person(){ FirstName="Steve", LastName="Jobs"},
new Person(){ FirstName="Lary", LastName="Page"},
new Person(){ FirstName="Bill", LastName="Gates"}
};
var allp = people1.Union(people2).ToArray();
Array.ForEach(allp, p => Console.WriteLine(p.FirstName));
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