Front-End Standard

Introduction

This document describes rules and recommendations for developing applications in .NET and class libraries using the C# Language. The goal is to define guidelines to enforce consistent style and formatting and help developers avoid common pitfalls and mistakes.

This document covers Naming Conventions, Coding Style, Language Usage, Object Model Design and Tips for developers.

Document Convention

Much like the ensuing coding standards, this document requires standards in order to ensure clarity when stating the rules and guidelines. Certain conventions are used throughout this document to add emphasis.

Below are some of the common conventions used throughout this document.

Coloring & Emphasis

Blue: Text colored blue indicates a keyword or .NET type.

Bold: Text with additional emphasis to make it stand-out.

Keywords

Always: Emphasizes this rule must be enforced.

Never: Emphasizes this action must not happen.

Do Not: Emphasizes this action must not happen.

Avoid: Emphasizes that the action should be prevented, but some exceptions may exist.

Try: Emphasizes that the rule should be attempted whenever possible and appropriate.

Example:Precedes text used to illustrate a rule or recommendation.

Reason: Explains the thoughts and purpose behind a rule or recommendation.

Terminology & Definitions

The following terminology is referenced throughout this document:

Access Modifier

C# keywords public, protected, internal, and private declare the allowed code-accessibility of types and their members. Although default access modifiers vary, classes and most other members use the default of private. Notable exceptions are interfaces and enums which both default to public.

Camel Case

A word with the first letter lowercase, and the first letter of each subsequent word-part capitalized.

Example: customerName

Common Type System

The .NET Framework common type system (CTS) defines how types are declared, used, and managed. All native C# types are based upon the CTS to ensure support for cross-language integration.

Identifier

A developer defined token used to uniquely name a declared object or object instance.

Example: public class MyClassNameIdentifier { … }

Pascal Case

A word with the first letter capitalized, and the first letter of each subsequent word-part capitalized.

Example: CustomerName

Premature Generalization

As it applies to object model design; this is the act of creating abstractions within an object model not based upon concrete requirements or a known future need for the abstraction. In simplest terms: “Abstraction for the sake of Abstraction.”

Flags

The following flags are used to help clarify or categorize certain statements:

Quick Summary This section contains tables describing a high-level summary of the major standards covered in this document. These tables are not comprehensive, but give a quick glance at commonly referenced elements.

Naming Conventions

• “c” = camelCase

• “P” = PascalCase

• “_” = Prefix with _Underscore

• “x” = Not Applicable.

Identifier	Public	Protected	Internal	Private	Notes
Project File	P	x	x	x	Match Assembly & Namespace.
Source File	P	x	x	x	Match contained class.
Other Files	P	x	x	x	Apply where possible.
Namespace	P	x	x	x	Partial Project/Assembly match.
Class or Struct	P	P	P	P	Add suffix of subclass.
Interface	P	P	P	P	Prefix with a capital I.
Source FileGeneric Class	P	P	P	P	Use T or K as Type identifier.
Method	P	P	P	P	Use a Verb or Verb-Object pair
Property	P	P	P	P	Do not prefix with Get or Set.
Field	P	P	v	_c	Only use Private fields.No Hungarian Notation!
Constant	P	P	P	_c
Static Field	P	P	P	_c	Only use Private fields.
Enum	P	P	P	P	Options are also Pascal Case.
Delegate	P	P	P	P
Event	P	x	x	x
Inline Variable	x	x	x	c	Avoid single-character and enumerated names.
Parameter	P	x	x	c

Coding Style

Code	Style
Source Files	One Namespace per file and one class per file.
Curly Braces	On new line. Always use braces when optional.
Indention	Use tabs with size of 4.
Comments	Use // or /// but not /* … */ and do not flowerbox.
Variables	One variable per declaration.

Language Usage

Code	Style
Native Data Types	Use built-in C# native data types vs .NET CTS types. (Use int NOT Int32)
Enums	Avoid changing default type.
Generics	Prefer Generic Types over standard or strong-typed classes.
Properties	Never prefix with Get or Set.
Methods	Use a maximum of 7 parameters.
base and this	Use only in constructors or within an override.
Ternary conditions	Avoid complex conditions.
for each statements	Do not modify enumerated items within a foreach statement.
Conditionals	Avoid evaluating Boolean conditions against true or false.No embedded assignment.Avoid embedded method invocation.
Exceptions	Do not use exceptions for flow control.Use throw; not throw e; when re-throwing.Only catch what you can handle.Use validation to avoid exceptions.Derive from Execption not ApplicationException.
Events	Always check for null before invoking.
Locking	Use lock() not Monitor.Enter().Do not lock on an object type or “this”.Do lock on private objects.
Dispose() & Close()	Always invoke them if offered, declare where needed.
Finalizers	Avoid.Use the C# Destructors.Do not create Finalize() method.
Assembly Version	Increment manually.
ComVisibleAttribute	Set to false for all assemblies

Naming Conventions

Consistency is the key to maintainable code. This statement is most true for naming your projects, source files, and identifiers including Fields, Variables, Properties, Methods, Parameters, Classes, Interfaces, and Namespaces.

General Guidelines

• Always use Camel Case or Pascal Case names.
• Avoid ALL CAPS and all lowercase names. Single lowercase words or letters are acceptable.
• Do not create declarations of the same type (namespace, class, method, property, field, or parameter) and access modifier (protected, public, private, internal) that vary only by capitalization.
• Do not use names that begin with a numeric character.
• Do add numeric suffixes to identifier names.
• Always choose meaningful and specific names.
• Variables and Properties should describe an entity not the type or size.
• Do not use Hungarian Notation!

Example: strName or iCount

• Avoid using abbreviations unless the full name is excessive.
• Avoid abbreviations longer than 5 characters.
• Any Abbreviations must be widely known and accepted.
• Use uppercase for two-letter abbreviations, and Pascal Case for longer abbreviations.
• Do not use C# reserved words as names.
• Avoid naming conflicts with existing .NET Framework namespaces, or types.
• Avoid adding redundant or meaningless prefixes and suffixes to identifiers

Example: // Bad! public enum ColorsEnum {…} public class CVehicle {…} public struct RectangleStruct {…}

• Do not include the parent class name within a property name.

Example: Customer.Name NOT Customer.CustomerName

• Try to prefix Boolean variables and properties with “Can”, “Is” or “Has”.
• Append computational qualifiers to variable names like Average, Count, Sum, Min, and Max where appropriate.
• When defining a root namespace, use a Product, Company, or Developer Name as the root. Example: SmartHCM.StringUtilities

Identifier	Naming Convention
Project File	Pascal Case.Always match Assembly Name & Root Namespace.Example:SmartHCM.Web.csproj -> SmartHCM.Web.dll -> namespace SmartHCM.Web
Source File	Pascal Case.Always match Class name and file name.Avoid including more than one Class, Enum (global), or Delegate (global) per file. Use a descriptive file name when containing multiple Class, Enum, or Delegates.Example:MyClass.cs => public class MyClass{…}
ResourceorEmbedded File	Try to use Pascal Case.Use a name describing the file contents.
Namespace	Pascal Case.Try to partially match Project/Assembly Name.Example:namespace SmartHCM.Web{…}
Class or Struct	Pascal Case.Use a noun or noun phrase for class name.Add an appropriate class-suffix when sub-classing another type when possible.Examples: private class MyClass {…}internal class SpecializedAttribute : Attribute {…}public class CustomerCollection : CollectionBase {…}
	public class CustomEventArgs : EventArgs {…}private struct ApplicationSettings{…}
Interface	Pascal Case.Always prefix interface name with capital “I”.Example:interface ICustomer{…}
Generic Class & Generic Parameter Type	Always use a single capital letter, such as T or K.Example:public class FifoStack<T>{public void Push(<T> obj){…}public <T> Pop(){…}}
Method	Pascal Case.Try to use a Verb or Verb-Object pair.Example:public void Execute() {…}private string GetAssemblyVersion(Assembly target) {…}
Property	Pascal Case.Property name should represent the entity it returns. Never prefix property names with“Get” or “Set”.Example:public string Name{get{…}set{…}}
Field(Public, Protected,or Internal)	Pascal Case.Avoid using non-private Fields!Use Properties instead.Example:public string Name;protected IList InnerList;
Field (Private)	Camel Case and prefix with a single underscore (_) character.Example:private string _name;
Constant orStatic Field	Treat like a Field.Choose appropriate Field access-modifier above.
Enum	Pascal Case (both the Type and the Options).Add the FlagsAttribute to bit-mask multiple options.Example:public enum CustomerTypes{Consumer,Commercial}
Delegate or Event	Treat as a Field.Choose appropriate Field access-modifier above.
	Example:public event EventHandler LoadPlugin;
Variable (inline)	Camel Case.Avoid using single characters like “x” or “y” except in FOR loops.Avoid enumerating variable names like text1, text2, text3 etc.
Parameter	Camel Case.Example:public void Execute(string commandText, int iterations){…}

Coding Style

Coding style causes the most inconsistency and controversy between developers. Each developer has a preference, and rarely are two the same. However, consistent layout, format, and organization are key to creating maintainable code.

The following sections describe the preferred way to implement source code in order to create readable, clear, and consistent code that is easy to understand and maintain.

Formatting

• Never declare more than 1 namespace per file.
• Avoid putting multiple classes in a single file.
• Always place curly braces ({ and }) on a new line.
• Curly braces ( {} ) should be in the same level as the code outside the braces.

Example: if ( … ) { // Do something! // … return false; }

• Always use curly braces ({ and }) in conditional statements.
• Always use a Tab & Indention size of 4.
• Use one blank line to separate logical groups of code.
• There should be one and only one single blank line between each method inside the class.
• Declare each variable independently – not in the same statement.
• Place namespace “using” statements together at the top of file. Group .NET namespaces above custom namespaces.
• Group internal class implementation by type in the following order:

a.Member variables. b.Constructors & Finalizers. c.Nested Enums, Structs, and Classes. d.Properties e.Methods

• Sequence declarations within type groups based upon access modifier and visibility:

a.Public b.Protected c.Internal d.Private

• Segregate interface Implementation by using #region statements.
• Use #region to group related pieces of code together. If you use proper grouping using #region, the page should like this when all definitions are collapsed.

Example:

• Recursively indent all code blocks contained within braces.
• Use white space (CR/LF, Tabs, etc) liberally to separate and organize code.

Code Commenting

• All comments should be written in the same language, be grammatically correct, and contain appropriate punctuation.
• Use // or /// but never /* … */
• Do not “flowerbox” comment blocks.

Example: // *************************************** // Comment block // ***************************************

• Use inline-comments to explain assumptions, known issues, and algorithm insights.
• Do not use inline-comments to explain obvious code. Well written code is self documenting.
• Only use comments for bad code to say “fix this code” – otherwise remove, or rewrite the code!
• Include comments using Task-List keyword flags to allow comment-filtering.

Example: // TODO: Place Database Code Here // UNDONE: Removed P\Invoke Call due to errors // HACK: Temporary fix until able to refactor

• Always apply C# comment-blocks (///) to public, protected, and internal declarations.
• Only use C# comment-blocks for documenting the API.
• Always include <summary> comments. Include <param>, <return>, and <exception> comment sections where applicable.
• Include <see cref=””/> and <seeAlso cref=””/> where possible.
• Always add CDATA tags to comments containing code and other embedded markup in order to avoid encoding issues.

Example: /// <example> /// Add the following key to the “appSettings” section of your config: /// <![CDATA[ /// <configuration> /// <appSettings> /// <add key=”mySetting” value=”myValue”/> /// </appSettings> /// </configuration> /// ]]> /// </example>

General

• Do not omit access modifiers. Explicitly declare all identifiers with the appropriate access modifier instead of allowing the default.

Example: // Bad! void WriteEvent(string message) {…} // Good! private void WriteEvent(string message) {…}

• Do not use the default (“1.0.*”) versioning scheme. Increment the AssemblyVersionAttribute value manually.
• Set the ComVisibleAttribute to false for all assemblies.
• Only selectively enable the ComVisibleAttribute for individual classes when needed.

Example: [assembly: ComVisible(false)] [ComVisible(true)] public MyClass {…}

• Consider factoring classes containing unsafe code blocks into a separate assembly.
• Avoid mutual references between assemblies.
• Use enum wherever required. Do not use numbers or strings to indicate discrete values.

Example: // Bad!

// Good!

Variables & Types

• Try to initialize variables where you declare them.
• Always choose the simplest data type, list, or object required.
• Always use the built-in C# data type aliases, not the .NET common type system (CTS).

Example: short NOT System.Int16 int NOT System.Int32 long NOT System.Int64 string NOT System.String

• Only declare member variables as private. Use properties to provide access to them with public, protected, or internal access modifiers.
• Try to use int for any non-fractional numeric values that will fit the int datatype - even variables for nonnegative numbers.
• Only use long for variables potentially containing values too large for an int.
• Try to use double for fractional numbers to ensure decimal precision in calculations.
• Only use float for fractional numbers that will not fit double or decimal.
• Avoid using float unless you fully understand the implications upon any calculations.
• Try to use decimal when fractional numbers must be rounded to a fixed precision for calculations. Typically this will involve money.
• Avoid using sbyte, short, uint, and ulong unless it is for interop (P/Invoke) with native libraries.
• Avoid specifying the type for an enum - use the default of int unless you have an explicit need for long (very uncommon).
• Avoid using inline numeric literals (magic numbers). Instead, use a Constant or Enum.
• Avoid declaring string literals inline. Instead use Resources, Constants and Configuration Files, Registry or other data sources.
• Declare readonly or static readonly variables instead of constants for complex types.
• Only declare constants for simple types.
• Avoid direct casts. Instead, use the “as” operator and check for null.

Example: object dataObject = LoadData(); DataSet ds = dataObject as DataSet; if(ds != null) {…}

• Always prefer C# Generic collection types over standard or strong-typed collections.
• Always explicitly initialize arrays of reference types using a for loop.
• Avoid boxing and unboxing value types.

Example: int count = 1; object refCount = count; // Implicitly boxed. int newCount = (int)refCount; // Explicitly unboxed.

• Floating point values should include at least one digit before the decimal place and one after.

Example: totalPercent = 0.05.

• Try to use the “@” prefix for string literals instead of escaped strings.
• Prefer String.Format() or StringBuilder over string concatenation.
• Never concatenate strings inside a loop.
• Do not compare strings to String.Empty or “” to check for empty strings. Instead, compare by using String.Length == 0.
• Avoid hidden string allocations within a loop. Use String.Compare() for case-sensitive

Example: (ToLower() creates a temp string) // Bad! int id = -1; string name = “lance hunt”; for(int i=0; i < customerList.Count; i++) { if(customerList[i].Name.ToLower() == name) { id = customerList[i].ID; } } // Good! int id = -1; string name = “lance hunt”; for(int i=0; i < customerList.Count; i++) { // The “ignoreCase = true” argument performs a // case-insensitive compare without new allocation. if(String.Compare(customerList[i].Name, name, true)== 0) { id = customerList[i].ID; } }

Flow Control

• Avoid invoking methods within a conditional expression.
• Avoid creating recursive methods. Use loops or nested loops instead.
• Avoid using foreach to iterate over immutable value-type collections. E.g. String arrays.
• Do not modify enumerated items within a foreach statement.
• Use the ternary conditional operator only for trivial conditions. Avoid complex or compound ternary operations.

Example: int result = isValid ? 9 : 4;

• Avoid evaluating Boolean conditions against true or false.

Example: // Bad! if (isValid == true) {…} // Good! if (isValid) {…}

• Avoid assignment within conditional statements.

Example: if((i=2)==2) {…}

• Avoid compound conditional expressions – use Boolean variables to split parts into multiple manageable expressions.

Example: // Bad! if (((value > _highScore) && (value != _highScore)) && (value < _maxScore)) {…} // Good! isHighScore = (value >= _highScore); isTiedHigh = (value == _highScore); isValid = (value < _maxValue); if ((isHighScore && ! isTiedHigh) && isValid) {…}

• Avoid explicit Boolean tests in conditionals.

Example: // Bad! if(IsValid == true) {…}; // Good! if(IsValid) {…}

• Only use switch/case statements for simple operations with parallel conditional logic.
• Prefer nested if/else over switch/case for short conditional sequences and complex conditions.
• Prefer polymorphism over switch/case to encapsulate and delegate complex operations.

Exceptions

• Do not use try/catch blocks for flow-control.
• Only catch exceptions that you can handle.
• Never declare an empty catch block.
• Avoid nesting a try/catch within a catch block.
• Always catch the most derived exception via exception filters.
• Order exception filters from most to least derived exception type.
• Avoid re-throwing an exception. Allow it to bubble-up instead.
• If re-throwing an exception, preserve the original call stack by omitting the exception argument from the throw statement.

Example: // Bad! catch(Exception ex) { Log(ex); throw ex; } // Good! catch(Exception) { Log(ex); throw; }

• Only use the finally block to release resources from a try statement.
• Always use validation to avoid exceptions.

Example: // Bad! try { conn.Close(); } Catch(Exception ex) // handle exception if already closed! } // Good! if(conn.State != ConnectionState.Closed) { conn.Close(); }

• Always set the innerException property on thrown exceptions so the exception chain & call stack are maintained.
• Avoid defining custom exception classes. Use existing exception classes instead.

Events, Delegates, & Threading

• Always check Event & Delegate instances for null before invoking.
• Use the default EventHandler and EventArgs for most simple events.
• Always derive a custom EventArgs class to provide additional data.
• Use the existing CancelEventArgs class to allow the event subscriber to control events.
• Always use the “lock” keyword instead of the Monitor type.
• Only lock on a private or private static object.

Example: lock(myVariable);

• Avoid locking on a Type.

Example: lock(typeof(MyClass));

• Avoid locking on the current object instance.

Example: lock(this);

Object Composition

• Always declare types explicitly within a namespace. Do not use the default “{global}” namespace.
• Avoid overuse of the public access modifier. Typically fewer than 10% of your types and members will be part of a public API, unless you are writing a class library.
• Consider using internal or private access modifiers for types and members unless you intend to support them as part of a public API.
• Never use the protected access modifier within sealed classes unless overriding a protected member of an inherited type.

Avoid declaring methods with more than 5 parameters. Consider refactoring this code.

• Try to replace large parameter sets (more than 5 parameters) with one or more class or struct parameters especially when used in multiple method signatures.
• Do not use the “new” keyword on method and property declarations.
• Only use the “base” keyword when invoking a base class constructor or base implementation within an override.
• Always validate an enumeration variable or parameter value before consuming it. They may contain any value that the underlying Enum type (default int) supports.

Example: public void Test(BookCategory cat) { if (Enum.IsDefined(typeof(BookCategory), cat)) {…} }

• Consider overriding Equals() on a struct.
• Always override the Equality Operator (==) when overriding the Equals() method.
• Always override the String Implicit Operator when overriding the ToString() method.
• Always call Close() or Dispose() on classes that offer it.
• Wrap instantiation of IDisposable objects with a “using” statement to ensure that Dispose() is automatically called.

Example: using(SqlConnection cn = new SqlConnection(_connectionString)) {…}

• Always implement the IDisposable interface & pattern on classes referencing external resources.

Example: public void Dispose() { Dispose(true); GC.SuppressFinalize(this); } protected virtual void Dispose(bool disposing) { if (disposing) { // Free other state (managed objects). } // Free your own state (unmanaged objects). // Set large fields to null. }

Object Model & API Design

• Always prefer aggregation over inheritance.
• Avoid “Premature Generalization”. Create abstractions only when the intent is understood.
• Do the simplest thing that works, then refactor when necessary.
• Always make object-behavior transparent to API consumers.
• Avoid unexpected side-affects when properties, methods, and constructors are invoked.
• Always separate presentation layer from business logic.
• Always prefer interfaces over abstract classes.
• Try to include the design-pattern names such as “Bridge”, “Adapter”, or “Factory” as a suffix to class names where appropriate.
• Only make members virtual if they are designed and tested for extensibility.

8Refactor often!

• Separate your application into multiple assemblies. Group all independent utility classes into a separate class library. All your database related files can be in another class library.

JavaScript Standards

This is a set of coding conventions and rules for use in JavaScript programming. All of our JavaScript code is sent directly to the public. It should always be of publication quality.

JavaScript features

Make sure that your code doesn't generate any strict JavaScript warnings, such as: •Duplicate variable declaration •Mixing return; with return value; •Trailing comma in JavaScript object declarations •Undeclared variables or members. •Don't compare booleans to true or false. For example, write if (ioService.offline). Compare objects to null, numbers to 0 or strings to "".

JavaScript Files

JavaScript programs should be stored in and delivered as .js files. JavaScript code should not be embedded in HTML files unless the code is specific to a single session. Code in HTML adds significantly to pageweight with no opportunity for mitigation by caching and compression. <script src=filename.js> tags should be placed as late in the body as possible. This reduces the effects of delays imposed by script loading on other page components.

Spaces, Linebreaks and Indentation

•Use two spaces for indentation. Don't use literal tab characters. •Put a space after control keywords like if and for. •Don't put spaces after function names. •Put a space after commas in argument lists. •The use of spaces can produce a larger filesize, but the size is not significant over local networks, and the difference is eliminated by minification.

Line Length

•Avoid lines longer than 70 characters. •When a statement will not fit on a single line, it may be necessary to break it. •Place the break after an operator, ideally after a comma. •The next line should be indented 8 spaces.

Comments

•Be generous with comments. •Strongly prefer // comments for making comments inside the bodies of functions and methods (this lets someone easily comment out a block of code while debugging later). •It is useful to leave information that will be read at a later time by people (possibly yourself) who will need to understand what you have done. •The comments should be well-written and clear. •It is important that comments be kept up-to-date. •Make comments meaningful. •Focus on what is not immediately visible. Don't waste the reader's time with stuff like oi = 0; // Set i to zero. •Generally use line comments. Save block comments for formal documentation.

Variable Declarations

•All variables should be declared before used. JavaScript does not require this, but doing so makes the program easier to read and makes it easier to detect undeclared variables. •The var statement should be the first statement in the function body. •It is preferred that each variable be given its own line and comment. Example: var currentEntry, // currently selected table entry level, // indentation level size; // size of table

Function Declarations

•All functions should be declared before they are used. •The function keyword must be followed by one space. •Inner functions should follow the var statement. This helps make it clear what variables are included in its scope. •There should be no space between the name of a function and the left parenthesis of its parameter list. •There should be one space between the right parenthesis and the left curly brace that begins the statement body. •The body itself is indented four spaces. •The right curly brace is aligned with the line containing the beginning of the declaration of the function. Example: function outer(c, d) {

       var e = c * d;

       function inner(a, b) {
           return (e * a) + b;
       }

       return inner(0, 1);

}

Function Calls

•Functions should be called with no spaces between the function name, the opening parenthesis, and the first parameter. •There should be one space between commas and each parameter, and there should not be a space between the last parameter, the closing parenthesis, and the semicolon. Example: var foobar = foo(bar, baz, quux); •There should be one space on either side of an equals sign used to assign the return value of a function to a variable.

Names, Case and Capitalization

•Names should be formed from the 26 upper and lower case letters, 10 digits and underscore. •Name methods and properties using camelCase. •Name global functions using camelCase. Avoid defining global functions. •Name constants using UPPERCASE. •Do not use $ (dollar sign) or \ (backslash) in names. •Do not use underscore as the first or last character of a name. It is sometimes intended to indicate privacy, but it does not actually provide privacy. •Variables and functions must use camelCase. In case a variable contains a jQuery object, the variable MUST start with a dollar sign ($): •Constructor functions that must be used with the new prefix should start with a capital letter. •Write true, false, and null in lowercase. •Global variables should be in all caps.

Statements

•Each line should contain at most one statement. •Put semicolon at the end of every simple statement. •All statements (except for, function, if, switch, try, while) MUST be followed by a semicolon. •JavaScript allows any expression to be used as a statement. The only expressions that should be used as statements are assignments. •A return statement with a value should not use parentheses around the value. •The return value expression must start on the same line as the return keyword. •Avoid use of the continue statement. It tends to obscure the control flow of the function.

Whitespace

•Blank lines improve readability by setting off sections of code that are logically related. •All code must not end with trailing whitespace. •A keyword followed by left parenthesis should be separated by a space. Example: while (true) {

Confusing Pluses and Minuses

Be careful to not follow a + with + or ++. This pattern can be confusing. Insert parenthesis between them to make your intention clear. Example: // Bad total = subtotal + +myInput.value; // Good total = subtotal + (+myInput.value);

ASP.NET Coding Standards

We will explore best practices in ASP.NET development in this section.

Choose pattern correctly

Choosing the correct pattern for your application development is a must.

It's not always that 3-Tier, MVC, MVP or MVVM is best; if you have a fixed small size system which is not going to be extended in the future then 1-Tier/2-Tier will be good.

DataTier

Always follow some guidelines for SQL queries.

•Never access database from the UI pages. Always have a data layer class which performs all the database related tasks. This will help you support or migrate to another database back end easily. •Separate your application into multiple assemblies. Group all independent utility classes into a separate class library. All your database related files can be in another class library. •Alias names like a,b,emp make queries unreadable and query management becomes very difficult. Use meaningful and proper alias names for tables. Example: TblEmployee Manager OR TblEmployee Developer. •If more than a single developer will work on a project then always put a description at the top of every procedure along with the creator name. •If in a query, in a where condition if a column with a primary key/unique key is involved, there is no need to put other conditions. Example: Select * FROM TblEmployee WHERE EmploeyeeId=@EmployeeId AND AccountId=@AccountId

App_Offline.htm file

Many people are unaware of this file. When you add a htm file name such as app_offline, every ASP.NET request will be redirected to this page. Use this page when you want to take your website offline temporarily, instead of writing your own logic for it.

Validation Controls

Use ASP.NET validation controls for validation because it supports both client side and server side validation.

Page.IsValid

Always check for this property value in Control events like Button_click when validation is being done using Validation Controls because it's easy to bypass JavaScript code.

Control State

While developing user controls if maintaining state is a must then use control states instead of viewstate.

Naming Convention

Always follow a consistent Naming Guidelines and standards, which should include everything. Use appropriate prefix for each of the UI element. A brief list is given below. Since .NET has given several controls, you may have to arrive at a complete list of standard prefixes for each of the controls (including third party controls) you are using.