Throwing Exceptions In Expressions In C# 7.0

In C# 7.0, the C# team introduced a new feature that allows developers to throw exceptions in Lambda expressions.

C#  version 7.0 introduced a new feature or we can say more flexible to throw the exceptions in Lambda expressions. Before seeing this, we know what we can do earlier in C# 6.0. 

Earlier up to C# 6.0, If you want to throw an exception we need to create a separate method and call that in respective expressions as follows,

public void ThrowingExceptionsInExpressionsOld()
{
    string obj = null;
    string noException = obj ? ? RaiseException();
}
public string RaiseException()
{
    throw new Exception("Object is null");
}

In the above code, we are trying to raise an exception via a new method in null coalescing expression. Now, from C# 7.0, we don't need to implement any additional method to raise an exception as above, instead, we can use direct throw statement in the expression. Following is the simplified code in C# 7.0. 

public void ThrowingExceptionsInExpressions()
{
    string obj = null;
    string noException = obj ? ?
        throw new Exception("Object is null");
}

The same way we can have a throw exceptions in Expression Bodied Constructors, Finalizers and Properties as well as while using conditional operators as shown below. 

string[] names = {};
string firstName = names.Length > 0 ? names[0] : throw new ApplicationException("Cannot set a default name");

As these changes doesn't effect much at runtime, but these features will improve readability and also simplifies the development. 

You can see complete code here in GitHub.

Happy Coding :)  

Learn more about Exception Handling in C#