CODEWITHSUNDEEP
swift
user6847532
user6847532

Reputation:

Constant 'XXX' used before being initialized

I am new in swift .. anyone help me to understand why this error throwing

Constant 'parsedResult' used before being initialized

on the other hand if i set return in the catch then compile error gone .what is the relation each other. explain please .

Here is my code :

 if let data = data {
     let parsedResult : AnyObject!
          do {
              parsedResult = try NSJSONSerialization.JSONObjectWithData(data, options: .AllowFragments)
                                            }
           catch{
                print("something  worng ")
                // return

             }
             // error compiler error this line 
                    print(parsedResult)
         }

Upvotes: 0

Views: 1637

Answers (2)

gnasher729
gnasher729

Reputation: 52530

This is easily fixed by declaring parseResult as AnyObject? which means it will be initialised to nil. The print will print an optional value which it can do just fine.

Be careful with the words you use. "// error throwing this line " is totally misleading. There is no error thrown at this line. Errors are thrown at runtime. You have the compiler reporting an error at this line. Be precise.

Upvotes: 1

Keiwan
Keiwan

Reputation: 8251

The way you have your code currently, parsedResult might be uninitialized when you reach the print(parsedResult) statement.

This can be the case when the try statement throws an error. parsedResult would still be uninitialized, the program would continue with the catch block, print "something wrong" and then just continue (trying to print parsedResult).

If you, however, insert a return in your catch block it ensures that in the case of an error, you wouldn't continue to the print(parsedResult) line.

Upvotes: 0

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