BEST PRACTICE
Returns
1. NULL Returns
– When returning a collection or enumerable ALWAYS return an empty enumerable/collection
String
1. String Concatenation
– Use StringBuilder instead of String concatenation
– string concatenation creates new memory allocation for new string
– stringBuilder uses the same memory
2. Always use string.IsNullOrEmpty() and string.IsNullOrWhiteSpace() whenever possible
LINQ
1. WHERE() with FIRST()
– Avoid using WHERE and First together or First when you are unsure that the result can be null.
– Use FirstOrDefault() where ever possible
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Rextester
{
public class Program
{
public static void Main(string[] args)
{
//INCORRECT
List numbers = new List{1,4,5,8,11,14,20,21,25,34,40};
int firstEven = numbers.Where(x => x % 2 == 0).First();
Console.WriteLine("First Even number : {0}", firstEven);
//CORRECT
int firstEvenCorrect = numbers.FirstOrDefault(x => x % 2 == 0);
Console.WriteLine("First Even number : {0}", firstEvenCorrect);
}
}
}
Casting
1. Cast by “as (T)” instead of “(T)”
| As (T) | (T) |
| Returns null when casting is not possible | Prefix casting will throw exception |
| Can be applied to reference type variable only | Prefix is free for all |
| Cannot perform user-defined conversions | Prefix can perform User defined conversion |
//INCORRECT var dog = (Dog)animal; //CORRECT var dog = animal as Dog;
Exceptions
1. Re-throwing exceptions
//INCORRECT throw ex; //CORRECT throw;
Enumerations
1. Use FOR LOOP for non collection eg array
2. Use FOR EACH for collection
3. Do not use OrderBy before Where clause
Keywords
1. Avoid using “ref” and “out” keywords as much as possible
Class
1. Always use properties instead of public variables
