C# 0 The Complete Reference

PART I

C h a p t e r   1 9 :  

L I N Q  

565

PART IPART I

Use let to Create a Variable in a Query

In a query, you will sometimes want to retain a value temporarily. For example, you might 

want to create an enumerable variable that can, itself, be queried. Or, you might want to 

store a value that will be used later on in a 

where

 clause. Whatever the purpose, these types 

of actions can be accomplished through the use of 

let

.

The

let

 clause has this general form:

let

name

 = 

expression

Here, 

name

 is an identifier that is assigned the value of 

expression.

 The type of 

name

 is 

inferred from the type of the expression.

Here is an example that shows how 

let

 can be used to create another enumerable data 

source. The query takes as input an array of strings. It then converts those strings into 

char

arrays. This is accomplished by use of another