Difference between IEnumerable VS IQueryable

   

IEnumerable

1. IEnumerable exists in System.Collections Namespace.
2. IEnumerable can move forward only over a collection, it can’t move backward and between the items.
3. IEnumerable is best to query data from in-memory collections like List, Array etc.
4. While query data from database, IEnumerable execute select query on server side, load data in-memory on client side and then filter data.
5. IEnumerable is suitable for LINQ to Object and LINQ to XML queries.
6. IEnumerable supports deferred execution.
7. IEnumerable doesn’t supports custom query.
8. IEnumerable doesn’t support lazy loading. Hence not suitable for paging like scenarios.
9. Extension methods supports by IEnumerable takes functional objects.
   
   
   
   

   IQueryable

   1. IQueryable exists in System.Linq Namespace.
   2. IQueryable can move forward only over a collection, it can’t move backward and between the items.
   3. IQueryable is best to query data from out-memory (like remote database, service) collections.
   4. While query data from database, IQueryable execute select query on server side with all filters.
   5. IQueryable is suitable for LINQ to SQL queries.
   6. IQueryable supports deferred execution.
   7. IQueryable supports custom query using CreateQuery and Execute methods.

Difference between disabled and read only attributes

Disabled attribute

1. Disabled form fields or elements values don’t post to the server for processing.
2. Disabled form fields or elements don’t get focus.
3. Disabled form fields or elements are skipped while tab navigation.
4. Some browsers (Like IE) provide default style (Gray out or emboss text) for disabled form fields or elements.

Read Only Attribute

1. Read Only form fields or elements values post to the server for processing.
2. Read Only form fields or elements get focus.
3. Read Only form fields or elements are included while tab navigation.
4. Some browsers do not provide default style for Read-Only form fields or elements. 

jQuery-Selecting elements with uncommon / special characters in ID or class name

Just add double backslashes \\ before any of the special characters 

HTML generated by some CMS or frameworks include elements with rather 
uncommon characters in ID or class names. For example, some may have 
special characters such as ‘.’ or ‘[..]’ in the ID or Class. To work 
around this, a selector in jQuery should be written this way:

Example 1 

$("$title.id") // won't work for ID: title.id

$("$title\\.id") // works for ID: title.id  

Example 2
$("$title[id]") // won't work for ID: title[id]

$("$title\\[id\\]") // works for ID: title[id]