Page 167 - CSharp/C#

Chapter 22: C# 3.0 Features

Remarks

C# version 3.0 was released as part of .Net version 3.5. Many of the features added with this
version were in support of LINQ (Language INtegrated Queries).

List of added features:

• LINQ
• Lambda expressions
• Extension methods
• Anonymous types
• Implicitly typed variables
• Object and Collection Initializers
• Automatically implemented properties
• Expression trees

Examples

Implicitly typed variables (var)

The var keyword allows a programmer to implicitly type a variable at compile time. var declarations
have the same type as explicitly declared variables.

var squaredNumber = 10 * 10;
var squaredNumberDouble = 10.0 * 10.0;
var builder = new StringBuilder();
var anonymousObject = new
{
One = SquaredNumber,
Two = SquaredNumberDouble,
Three = Builder
}

The types of the above variables are int, double, StringBuilder, and an anonymous type
respectively.

It is important to note that a var variable is not dynamically typed. SquaredNumber = Builder is not
valid since you are trying to set an int to an instance of StringBuilder

Language Integrated Queries (LINQ)

//Example 1
int[] array = { 1, 5, 2, 10, 7 };

// Select squares of all odd numbers in the array sorted in descending order
IEnumerable<int> query = from x in array

https://riptutorial.com/ 113