Question

I have an array of string :

string[] PropertyIds= new string[5];

A List of Class(Property)

List<Property> properties = new List<Property>();

The class Property has following fields:
PropertyId (string) and PropertyDesc (string)

I have to find all the values of PropertyId in array PropertyIds, which are not in List properties.

e.g.

 string[] PropertyIds= new string[] { "one", "two", "three" };
List<Property> properties = new List<Property>()
{ 
  new Property("one","This is p1"),
  new Property("Five","This is p5"),   
  new Property("six","This is p6"),
};

Then my result should be two and three.

Answer 1

Use Enumerable.Except to get difference from two sequences:

var result = PropertyIds.Except(properties.Select(p => p.PropertyId));