Phone Number Analysis

Tuples

In C#, a tuple is a data structure which organizes data, holding two or more fields of any type.

A tuple is typically created by placing 2 or more expressions separated by commas, within a set of parentheses.

string boast = "All you need to know";
bool success = !string.IsNullOrWhiteSpace(boast);
(bool, int, string) triple = (success, 42, boast);

A tuple can be used in assignment and initialization operations, as a return value or a method argument.

Fields are extracted using dot syntax. By default, the first field is Item1, the second Item2, etc. Non-default names are discussed below.

// initialization
(int, int, int) vertices = (90, 45, 45);

// assignment
vertices = (60, 60, 60);

//  return value
(bool, int) GetSameOrBigger(int num1, int num2)
{
    return (num1 == num2, num1 > num2 ? num1 : num2);
}

// method argument
int Add((int, int) operands)
{
    return operands.Item1 + operands.Item2;
}

Field names Item1 etc. do not make for readable code. The code below shows 2 ways to name the fields of tuples. Note also, in the code below, that var can be used with tuples and the type inferred. This works equally well for tuples with named and unnamed fields.

// name items in declaration
(bool success, string message) results = (true, "well done!");
bool mySuccess = results.success;
string myMessage = results.message;

// name items in creating expression
var results2 = (success: true, message: "well done!");
bool mySuccess2 = results2.success;
string myMessage2 = results2.message;