Vernacular C # tuples of new syntax features,

Vernacular C # tuples of new syntax features,

1. Tuple)

Tuple comes in 4.0, but it also has some disadvantages, such:

1) Tuple affects code readability because its attribute names are Item1, Item2...

2) Tuple is not lightweight enough because it is a reference type (Class). It is unnecessary to use a type for a variable.

The source code is as follows:

1 // 2 // Summary: 3 // provides a static method for creating a tuples object. To browse the Source code of this type of. NET Framework, see Reference Source. 4 public static class Tuple 5 {6 // return result: 7 // a Tuple with its value (item1 ). 8 public static Tuple <T1> Create <T1> (T1 item1); 9 10 // return result: 11 // a 2-tuples with values (item1, item2 ). 12 public static Tuple <T1, T2> Create <T1, T2> (T1 item1, T2 item2); 13}

Provides static methods for creating tuples.

 

Note: The Tuple mentioned above is not lightweight enough. In a sense, it is a hypothesis that there are many Allocation Operations.

The ValueTuple in C #7 solves the preceding two disadvantages:

1) ValueTuple supports semantic field naming. You can customize the name for each attribute name. For example, (int first, int second) tuple = ).

2) ValueTuple is a value type (Struct ).

NOTE: If vs reports an error that does not have a pre-defined ValueTuple <...>, use the nuget command to import: Install-Package System. ValueTuple

The source code is as follows (ValueTuple <...> internal principle ):

 1     public struct ValueTuple<T1, T2> : IEquatable<ValueTuple<T1, T2>>, IStructuralEquatable, IStructuralComparable, IComparable, IComparable<ValueTuple<T1, T2>>, ITupleInternal 2     { 3         public T1 Item1; 4         public T2 Item2; 5         int ITupleInternal.Size 6         { 7             get 8             { 9                 return 2;10             }11         }12         public ValueTuple(T1 item1, T2 item2)13         {14             this.Item1 = item1;15             this.Item2 = item2;16         }17          }

ValueTuple (structure)

Summary: The appearance of tuples simplifies object orientation to a certain extent. Some unnecessary or rarely used objects can be directly returned using tuples without returning them by type.