What and When to use Tuple?

May someone please explain what a Tuple is and how to use it in a Real World Scenario. I would like to find out how this can enrich my coding experience?

This msdn article explains it very well with examples, "A tuple is a data structure that has a specific number and sequence of elements".

> Tuples are commonly used in four ways: > > 1. To represent a single set of data. For example, a tuple can > represent a database record, and its components can represent > individual fields of the record. > > 2. To provide easy access to, and manipulation of, a data set. > > 3. To return multiple values from a method without using out parameters > (in C#) or ByRef parameters (in Visual Basic). > > 4. To pass multiple values to a method through a single parameter. For > example, the Thread.Start(Object) method has a single parameter that > lets you supply one value to the method that the thread executes at > startup time. If you supply a Tuple<T1, T2, T3> object as the method > argument, you can supply the thread’s startup routine with three > items of data.

A tuple allows you to combine multiple values of possibly different types into a single object without having to create a custom class. This can be useful if you want to write a method that for example returns three related values but you don't want to create a new class.

Usually though you should create a class as this allows you to give useful names to each property. Code that extensively uses tuples will quickly become unreadable because the properties are called Item1, Item2, Item3, etc..

The difference between a tuple and a class is that a tuple has no property names. This is almost never a good thing, and I would only use a tuple when the arguments are fairly meaningless like in an abstract math formula Eg. abstract calculus over 5,6,7 dimensions might take a tuple for the coordinates.

This is the most important thing to know about the Tuple type. Tuple is a class, not a struct. It thus will be allocated upon the managed heap. Each class instance that is allocated adds to the burden of garbage collection.

Note: The properties Item1, Item2, and further do not have setters. You cannot assign them. The Tuple is immutable once created in memory.

Tuple classes allow developers to be 'quick and lazy' by not defining a specific class for a specific use.

The property names are Item1, Item2, Item3 ..., which may not be meaningful in some cases or without documentation.

Tuple classes have strongly typed generic parameters. Still users of the Tuple classes may infer from the type of generic parameters.