Question

Suppose we have a case where a variable is declared in certain conditions:

if (x = 1)
 boolean z = true;

Later on, we’d like to test if the variable z exists with try-catch. Is this possible and if so, what exception should we catch?

try {
 if (z)
  //do smth
} catch (<exception?> ex) {
 //do smth_else
}

Of course it would be possible to declare z before and change it’s value accordingly in if block, but just hypothetically, is the above possible in Java?
Python for example has NameError that will be raised when accessed local or global variable is not declared.

Thanks!

HSI.

Answer 1

Suppose we have a case where a variable is declared in certain conditions:

Well it is difficult to assume because that would not compile:

• you should use == to test for equality
• you can’t declare a variable in an if statement unless there is a block

Now assuming you enclose that declaration inside a block, the scope of that variable would be that block and you wouldn’t be able to use it in your try / catch block (unless it is inside the if block of course, but I don’t think that’s what you want).