Throwing Exceptions In Expressions - C# 7.0

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

In C# 7.0, they have 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,

  1. public void ThrowingExceptionsInExpressionsOld()  
  2. {  
  3.     string obj = null;  
  4.     string noException = obj ? ? RaiseException();  
  5. }  
  6. public string RaiseException()   
  7. {  
  8.     throw new Exception("Object is null");  
  9. }  

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. 

  1. public void ThrowingExceptionsInExpressions()  
  2. {  
  3.     string obj = null;  
  4.     string noException = obj ? ?  
  5.         throw new Exception("Object is null");  
  6. }  

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. 

  1. string[] names = {};   
  2. 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 :)