Alternate way of writing multiple conditions inside IF statement for conditional checking

Suppose we have a requirement like we want to check if a particular input string matches or not

Generally we write as under

var input = "xyz";
if (input != "a")
{
  Console.WriteLine("Not matched");
}
else
{
  Console.WriteLine("matched");
}

output
---------
Not matched

Ok.That's fine. Now consider, we have two such condition to check, so generally we go ahead as under

var input = "xyz";
if (input != "a" && input != "b")
{
  Console.WriteLine("Not matched");
}
else
{
  Console.WriteLine("matched");
}

output
---------
Not matched

If there is a third condition to check , so it will be

if (input != "a" && input != "b" && input != "c")

And so on...So if there are many such conditions to check we need to write many such conditional statements inside "If" which is difficult to maintain and less readable.

An alternate and cleaner way is to put them inside an array and search if the string is present or not as under

var input = "c";
var recordCount = new string[] { "a", "b","c","d" }.Where(i => i == input).Count();           
var result = (recordCount == 0) ? "Not matched":"matched";
Console.WriteLine(result);

In this method, we find that only we need to extend the array if some more requirement comes.It is readable and maintainable too.

Thanks for reading

Best Regards,
Niladri Biswas

if(ConditionOne && ConditionTwo && ConditionThree)
{
Code to execute
}

Second example:-

if(ConditionOne)
{
if(ConditionTwo )
{
if(ConditionThree)
{
Code to execute
}
}
}


Premalatha
Software Engineer

The code of yours get's into the same problem of maintenance.That is what I tried to address in the example given. (:

Best Regards,
Niladri Biswas

Indeed its a better way, less line of code too. However we need to check for its speed in comparison with the traditional if else. As internally this is also doing the same thing (using linq).

A finding of speed comparison would be nice thing to see.

Thanks

Regards,
Sheo Narayan, Microsoft MVP
230+ ASP.NET Tips and Tricks - http://www.itfunda.com/Howto