C# 7.0 introduces a new tuple syntax that allows you to group multiple values together using a clean, lightweight syntax. Unlike the older Tuple<T1, T2> class, these new tuples use value types for better performance and support named elements for improved readability.

Tuples are particularly useful for returning multiple values from methods without creating a dedicated class or struct, or for temporarily grouping related values.

Code

Now

(string name, int age) GetPerson()
{
    return ("Alice", 30);
}

var person = GetPerson();
Console.WriteLine(person.name);

Before

Tuple<string, int> GetPerson()
{
    return Tuple.Create("Alice", 30);
}
var person = GetPerson();
Console.WriteLine(person.Item1);

Notes

• You can either:
  • Use named elements when declaring the tuple type (string name, int age) and access them by name
  • Use unnamed elements and access them by position Item1, Item2, etc.
  • Infer names ^{C# 7.1} from variable names when creating tuples var tuple = (name, age);
• Tuples support deconstruction ^{C# 7.0} allowing you to extract individual values directly
• Tuples are value types (specifically ValueTuple<T1, T2, ...>) unlike the older reference-type Tuple class
• Element names are compile-time only and don't exist at runtime, so reflection will only see Item1, Item2, etc.

More information

• What's new in C# 7.0
• Tuple types (C# reference)
• Tuples in C# 7 @ Thomas Levesque