Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
What is Pattern Matching in C# 7.0?
C# 7.0 introduces pattern matching in two cases, the is expression and the switch statement.
Patterns test that a value has a certain shape, and can extract information from the value when it has the matching shape.
Pattern matching provides more concise syntax for algorithms
You can perform pattern matching on any data type, even your own, whereas with if/else, you always need primitives to match.
Pattern matching can extract values from your expression.
Before Pattern Matching −
Example
public class PI{
public const float Pi = 3.142f;
}
public class Rectangle : PI{
public double Width { get; set; }
public double height { get; set; }
}
public class Circle : PI{
public double Radius { get; set; }
}
class Program{
public static void PrintArea(PI pi){
if (pi is Rectangle){
Rectangle rectangle = pi as Rectangle;
System.Console.WriteLine("Area of Rect {0}", rectangle.Width * rectangle.height);
}
else if (pi is Circle){
Circle c = pi as Circle;
System.Console.WriteLine("Area of Circle {0}", Circle.Pi * c.Radius * c.Radius);
}
}
public static void Main(){
Rectangle r1 = new Rectangle { Width = 12.2, height = 33 };
Rectangle r2 = new Rectangle { Width = 12.2, height = 44 };
Circle c1 = new Circle { Radius = 12 };
PrintArea(r1);
PrintArea(r2);
PrintArea(c1);
Console.ReadLine();
}
}Output
Area of Rect 402.59999999999997 Area of Rect 536.8 Area of Circle 452.44799423217773
After Pattern Matching −
Example
public class PI{
public const float Pi = 3.142f;
}
public class Rectangle : PI{
public double Width { get; set; }
public double height { get; set; }
}
public class Circle : PI{
public double Radius { get; set; }
}
class Program{
public static void PrintArea(PI pi){
if (pi is Rectangle rectangle){
System.Console.WriteLine("Area of Rect {0}", rectangle.Width *
rectangle.height);
}
else if (pi is Circle c){
System.Console.WriteLine("Area of Circle {0}", Circle.Pi * c.Radius *
c.Radius);
}
}
public static void Main(){
Rectangle r1 = new Rectangle { Width = 12.2, height = 33 };
Rectangle r2 = new Rectangle { Width = 12.2, height = 44 };
Circle c1 = new Circle { Radius = 12 };
PrintArea(r1);
PrintArea(r2);
PrintArea(c1);
Console.ReadLine();
}
}Output
Area of Rect 402.59999999999997 Area of Rect 536.8 Area of Circle 452.44799423217773
Updated on: 19-Aug-2020
218 Views
Advertisements