if statement for throwing Exception?

Question

Hi I wanted to ask because I'm not sure if is it propriete using of Exception:

public int Method(int a, int b) {    if(a<b) throw new ArgumentException("the first argument cannot be less than the second");    //do stuff...  } 

can I throw Exception after if statement? or should I always use try - catch when it goes with the exceptions?

Answer 1

That is perfectly valid. That is exactly what exceptions are used for, to check for "Exceptions" in your logic, things that weren't suppose to be.

The idea behind catching an exception is that when you pass data somewhere and process it, you might not always know if the result will be valid, that is when you want to catch.

Regarding your method, you don't want to catch inside Method but infact when you call it, here's an example:

try {     var a = 10;     var b = 100;     var result = Method(a, b); } catch(ArgumentException ex)  {     // Report this back to the user interface in a nice way  } 

In the above case, a is less than b so you can except to get an exception here, and you can handle it accordingly.