LINQ query syntax in C Sharp (C#) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does LINQ stand for in C#?

LINQ stands for Language Integrated Query. It allows querying data in a readable and concise way directly in C# code.

beginner

What is the basic structure of a LINQ query using query syntax?

A LINQ query using query syntax typically has this structure:<br>

from item in collection<br>where condition<br>select item

It reads like a sentence: from a collection, pick items that meet a condition, then select them.

beginner

How do you filter elements in a LINQ query syntax?

You use the where keyword to filter elements. For example:<br>

from num in numbers<br>where num > 5<br>select num

This selects numbers greater than 5.

intermediate

Can you use multiple conditions in a LINQ query's where clause?

Yes, you can combine conditions using logical operators like && (and) or || (or).<br>Example:<br>

from item in collection<br>where item.Age > 18 && item.IsActive<br>select item

beginner

What keyword do you use in LINQ query syntax to order results?

You use the orderby keyword to sort results.<br>Example:<br>

from num in numbers<br>orderby num descending<br>select num

This orders numbers from highest to lowest.

Which keyword starts a LINQ query in query syntax?

A from

B select

C where

D orderby

A LINQ query starts with the from keyword to specify the data source.

How do you select only items where a number is greater than 10?

A where num &lt; 10

B select num &gt; 10

C orderby num &gt; 10

D where num &gt; 10

The where clause filters items. Use where num > 10 to select numbers greater than 10.

Which keyword is used to sort results in LINQ query syntax?

A sortby

B orderby

C arrange

D filter

The orderby keyword sorts the results in ascending or descending order.

What does the select keyword do in a LINQ query?

A Starts the query

B Filters data

C Specifies the output of the query

D Sorts the data

select defines what the query returns, like which fields or objects.

Can you use multiple where clauses in one LINQ query?

A Yes, multiple <code>where</code> clauses can be chained

B No, only one <code>where</code> is allowed

C Yes, but only one is effective

D Only if combined with <code>orderby</code>

You can chain multiple where clauses to filter data step by step.

Explain the basic structure of a LINQ query using query syntax and how it works.

Think about how you pick items from a list based on conditions.

Describe how to filter and sort data using LINQ query syntax with examples.

Filtering is like choosing only what you want; sorting is arranging them.