Filtering data in LINQ with the help of where clause

LINQ has bought with itself a super power of querying Objects, Database, XML, SharePoint and nearly any other data structure. The power of LINQ lies in the fact that it is managed code that lets you write SQL type code to fetch data. 

Whenever working with data we always need a way to filter out the data based on different condition. In this post we will look at some of the different ways in which we can filter data in LINQ with the help of where clause.

Simple Filter for an array.

Let’s say we have an array of number and we want to filter out data based on some condition. Below is an example

int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };

var lowNums =

                from num in numbers

                where num < 5

                select num;

Filter based on one of the property in the class.

With the help of LINQ we can also filer out data from a list based on value of some property.

var soldOutProducts =

                from prod in products

                where prod.UnitsInStock == 0

                select prod;

Filter based on Multiple of the property in the class.

var expensiveInStockProducts =

        from prod in products

        where prod.UnitsInStock > 0 && prod.UnitPrice > 3.00M

        select prod;

Filter based on the index of the Item in the list.
In the below example we can see that we are able to filter data based on the index of the item in the list.

string[] digits = { "zero", "one", "two", "three", "four", "five", "six"};

var shortDigits = digits.Where((digit, index) => digit.Length < index);

There are many other way in which we can filter out data in LINQ. In the above post I have tried and shown few ways using the LINQ.

Vikram