C# developers have always used throw statement to throw unhandled exceptions to caller. A reactive programming approach involved validating the variable values and if it doesn’t fall within a valid range or is null throw exception as demonstrated in below example

//Method that fetches data from server 
object Getdata()
        {
            //Fetch data from server or database and if data is null return null
            return null;//
        }

        private void btnThrowExpressionAlternateC6_Click(object sender, EventArgs e)
        {
            var data = Getdata();
            if (data == null)
                throw new Exception("No Data found");

        }

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As you can see if data is null we create a custom exception and throw to caller. A shorthand syntax would have been to use null coalescing operator (??) to check if GetData method returns  null and throw exception but since throw is a statement below syntax didn’t work in older versions of C# but it does in C# 7.0

private void btnThrowExpressionAlternateC7_Click(object sender, EventArgs e)
        {
//Short and Concise . We cannot do that in C# 6 since ?? operator requires types on left hand side and right hand 
            //side to be identical but with expressions this is supported
            var data = Getdata() ?? throw new Exception("No Data found");
        }

All code samples are available at my GitHub profile

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