Initializing nested object properties

Question

I have a class called employee which has a field called insurance which is of type insurance like this

public class Employee
{
    public string Name;
    public Insurance Insurance;
}

I have another class called Insurance

public class Insurance
{
    public int PolicyId;
    public String PolicyName;
}

Now in the main program i want to do something like

var myEmployee = new Employee();
myEmployee.Name = "Jhon";
myEmployee.Insurance.PolicyId = 123 ;
myEmployee.Insurance.PolicyName = "Life Time" ;

C# is complaining and i know how to fix it by creating a instance of the Insurance class.

My question is can i somehow assign the values for the fields in the way i want to do it in the main program using like

**

myEmployee.Insurance.PolicyId = 123 ;
myEmployee.Insurance.PolicyName = "Life Time" ;

** I tried

 public class Employee
    {

        public Employee()
        {
            Insurance Insurance = new Insurance();
        }

        public String Name;
        public Insurance Insurance;



        public class Insurance
        {
            public int PolicyId;
            public String PolicyName;
        } 
    }

In the main method when i try

class Program
    {
        static void Main(string[] args)
        {
            var joe = new Employee();
            joe.Name = "Joe";
            joe.Insurance.

        }

I get this error-

Error 2 Ambiguity between 'ConsoleApplication1.Employee.Insurance' and 'ConsoleApplication1.Employee.Insurance' c:\users\lenovo\documents\visual studio 2012\Projects\ConsoleApplication1\ConsoleApplication1\Program.cs 15 17 ConsoleApplication1

I want to use myEmployee.Insurance.PolicyId using 2 dots.Is this even possible in any object oriented langauge . — jhon.smith
– jhon.smith, Commented Aug 8, 2013 at 18:37
You defined a class "Insurance" and a property "Insurance" both within Employee. Must be uniquely named within the class, otherwise it won't know which to work on. Make Insurance it's own class, or rename one of them. I updated my answer to reflect your edits and resolve this. — bland
– bland, Commented Aug 8, 2013 at 20:05

bland · Accepted Answer · 2013-08-08 20:08:42Z

17

You could instantiate Insurance in Employee's constructor so it is done automatically for you. You could provide it default values to ensure it is understood that is not yet defined to be valid when accessed later on.

public class Employee
{
    Insurance Insurance { get; set; }

    public Employee()
    {
        this.Insurance = new Insurance() { PolicyId = -1 };
    }
}

public class Insurance
{
    public int PolicyId { get; set; }
    public string PolicyName { get; set; }
}

Or to keep the classes nested:

public class Employee
{
    Insurance InsurancePolicy { get; set; }

    public Employee()
    {
        this.InsurancePolicy = new Insurance() { PolicyId = -1 };
    }
    public class Insurance
    {
        public int PolicyId { get; set; }
        public string PolicyName { get; set; }
    }
}

edited Aug 8, 2013 at 20:08

answered Aug 8, 2013 at 18:32

bland

2,0021 gold badge16 silver badges22 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Cᴏʀʏ · Accepted Answer · 2013-08-08 18:55:06Z

13

Without requiring changes to your Employee class, you could use object initializers:

var myEmployee = new Employee 
{
    Name = "Jhon",
    Insurance = new Insurance
    {
        PolicyId = 123,
        PolicyName = "Life Time"
    }
};

Alternatively, and maybe preferably, you can have the Employee class create a new instance of Insurance either in its constructor (as in the other answers), or one other option would be to do it in the Insurance property getter itself, so it's instantiated only if you use it. Here's an example of the latter:

class Employee 
{
    private Insurance insurance;

    public Insurance Insurance
    {
        get
        {
            if (insurance == null)
            {
                insurance = new Insurance();
            }
            return insurance;
        }
    }
}

Lastly, I would suggest that you don't build classes that have all public fields unless you really know that's what you want. Instead, I would consider using properties over fields. I have incorporated other's suggestions into the following code, and provided my own:

public class Employee
{
    public Employee() 
    {
        this.Insurance = new Insurance();
    }

    // Perhaps another constructor for the name?
    public Employee(string name)
        : this()
    {
        this.Name = name;
    }

    public string Name { get; set; }
    public Insurance Insurance { get; private set; }
}

public class Insurance
{
    public int PolicyId { get; set; }
    public string PolicyName { get; set; }
}

edited Aug 8, 2013 at 18:55

answered Aug 8, 2013 at 18:30

Cᴏʀʏ

108k20 gold badges169 silver badges201 bronze badges

3 Comments

KappaG3 Over a year ago

That singleton-like approach doesn't sound very useful in this case. Instantiating in the constructor is more than enough, and it also avoids a null-check every time Insurance is trying to be accessed.

KappaG3 Over a year ago

It would be better if the Insurance class was a heavy object, though. I'll give you that.

Cᴏʀʏ Over a year ago

@KappaG3: I agree 100%, just wanted to show another possible approach.

KappaG3 · Accepted Answer · 2013-08-08 18:48:36Z

6

Of course, but how are you going to assign something that is belonging to a null object? You need to instantiate Insurance in Employee's constructor.

public Employee()
{
     this.Insurance = new Insurance();
}

EDIT Regarding your comment: Following this approach you will be able to access myEmplyee.Insurance.PolicyID with two dots. The constructor is inside Employee's class, so you won't have to type anything more than what you already tried to do, once you implement it.

edited Aug 8, 2013 at 18:48

answered Aug 8, 2013 at 18:31

KappaG3

6717 silver badges15 bronze badges

1 Comment

Johan Over a year ago

I generally do this and prefer it over any other ways. It works great for instantiating collections.

Sam I am says Reinstate Monica · Accepted Answer · 2013-08-08 18:31:49Z

1

You can write a constructor for your employee that will instantiate Insurance

public class Employee
{
    public Employee()
    {
        this.Insurance = new Insurance();
    }
    public string Name;
    public Insurance Insurance;
}

answered Aug 8, 2013 at 18:31

Sam I am says Reinstate Monica

31.3k12 gold badges74 silver badges101 bronze badges

4 Comments

Fede Over a year ago

this keyword is redundant unless used for extension methods.

KappaG3 Over a year ago

It avoids confusion when the member's name is the same as its type.

Sam I am says Reinstate Monica Over a year ago

@HighCore the this keyword is more expressive, and it is useful when you're trying to read more complex code. especially when you're reading code that you yourself didn't write

Sam I am says Reinstate Monica Over a year ago

@jhon.smith the error you're getting is because there are 2 meanings to Employee.Insurance You might want to move your Insurance class to outside of Employee

Collectives™ on Stack Overflow

Initializing nested object properties

4 Answers 4

Comments

3 Comments

1 Comment

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

3 Comments

1 Comment

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related