Variable being used without being initialized c++

Question

I'm relatively new to C++. I'm using a function to give an object some values, but I keep getting the error that the object is being used without being initialized. How come?

The definition of Worker:

class Worker 
    public:
    int telephone;
    char firstname[20];
    char task[100];
    int salary;
    int id;
};

The actual code:

Worker worker1;
worker1 = getWorker(worker1);

Worker getWorker(Worker worker){
    cout << "First name: ";
    cin >> worker.firstname;
    return worker;

"I've done basically the same in Java" Yes, and as you may have noticed, they are not the same languages. — cadaniluk, Dec 12 '15 at 17:05
What's the exact diagnostic message? How is `Worker` defined? — cadaniluk, Dec 12 '15 at 17:05
Possible duplicate of [initializing static variable with a function call gives compilation error?](http://stackoverflow.com/questions/12720400/initializing-static-variable-with-a-function-call-gives-compilation-error) — Superlokkus, Dec 12 '15 at 17:06
Just avoid these kind of sentences. I'll not be the only one making fun of it. — cadaniluk, Dec 12 '15 at 17:09
Have you tried talking in France in English - That does not work either (well sometimes) — Ed Heal, Dec 12 '15 at 17:10
name of `get_worker` is misleading. And it's design seems flawed. — GingerPlusPlus, Dec 12 '15 at 17:13
Just curious as to why you think that two languages (programming or otherwise) would work the same — Ed Heal, Dec 12 '15 at 17:13
@EdHeal Just forget it. Do you know why I'm getting the error? — Jullix993, Dec 12 '15 at 17:14
@Jullix993: It is somewhat related -- you wouldn't get the error, if you didn't take `worker` as parameter. — GingerPlusPlus, Dec 12 '15 at 17:19
@GingerPlusPlus Yes I just noticed that, I don't understand that. I declared a Worker in the function instead of getting one in the parameter, and it worked. — Jullix993, Dec 12 '15 at 17:21

score 1 · Accepted Answer · answered Dec 12 '15 at 18:21

getWorker doesn't need an argument. Use a local object to get the input, and return it:

Worker getWorker() {
    Worker worker;
    // whatever
    return worker;
}

Also, use initialization instead of creating objects then assigning to them. Like this:

Worker worker1 = getWorker();

score 0 · Answer 2 · answered Dec 12 '15 at 17:15

As you haven't explicitly set the value of firstname there could be any kind of garbage stored in the 20 bytes that make up firstname. char buffers are 0 terminated, so best practice would be to give an initial value to firstname in a default constructor:

Worker(){
  //omitting other code
  firstname[0] = '\0';
}

Of course, if you want the variable to hold an actual value it would be best to pass it into the constructor.

Variable being used without being initialized c++

2 Answers2