field is never assigned to and will always have its default

Hmm.. one of my classes is having error with "field is never assigned to and will always have its default value 0" for "m_street""m_zipCode" "m_city" and "m_country;".
I think someone told me to initialize a variable, but I am not sure how to do it.
I tried this, but it didn't work:

private Address m_street = new Address();

/////////// My class below///////////////

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace Assignment_6_attempt_1

{

///

/// Handles addresses. Street, Zip code, City (3) / Street, zip code, city, and country (4)

///

class Address

{

//declaring variables

private string m_street;

private string m_zipCode;

private string m_city;

private Assignment_6_attempt_1.ContactFiles.Countries m_country;

private ContactFiles.Countries Countries;

///

/// Default constructor for calling another constructor in this class.

///

public Address() : this(string.Empty, string.Empty, "Malmo")

{

this.Street = null;

this.ZipCode = null;

this.City = "Malmo";

}

///

/// Constructor with 3 parameters

///

public Address(string street, string zip, string city)

: this(street, zip, city, Assignment_6_attempt_1.ContactFiles.Countries.Sverige)

{

this.Street = street;

this.ZipCode = zip;

this.City = city;

}

///

public Address(string street, string zip, string city, Assignment_6_attempt_1.ContactFiles.Countries country)

{

this.Street = street;

this.ZipCode = zip;

this.City = city;

this.Countries = country;

}

///

/// Properties

///

public string Street { get; set; }

public string City { get; set; }

public string ZipCode { get; set; }

public Assignment_6_attempt_1.ContactFiles.Countries Country { get; set; }

///

/// replaces "_" with space for the country enums

///

public string GetCountryString()

{

string strCountry = m_country.ToString();

strCountry = strCountry.Replace("_", " ");

return strCountry;

}

///

/// override the ToString method to return a string made of the address detail

///

public override string ToString()

{

string strOut = string.Format("{0, -25) {1,-8} {2, -10} {3}", m_street, m_zipCode, m_city, GetCountryString());

return strOut;

}

public string GetAddressLabel()

{

string strOut = Street + ZipCode + City + Country;

return strOut;

}

public bool Validate()

{

if (m_street != null)

{

return true;

}

return false;

}

When you create an object of a class, all its fields (i.e. class level variables) are automatically given their defaults values unless they've been initialized to something else.

The default values are zero for numbers, false for bool, '\0' for char and null for all reference types including strings.

You'll get a compiler warning if you fail to assign a definite value to a field though this is only a warning and the program will still compile (and hopefully run) if you don't do anything about it.

However, I think you have a more serious problem here in that the m_street, m_zipcode, m_city and m_country are duplicating the Street, Zipcode, City and Country 'automatic' properties.

When you have automatic properties, the compiler generates the backing fields automatically so you don't need to do this yourself.

I'd therefore remove the declaration of the 'm_' fields and change them to the properties when they're accessed in the executable code. This should hopefully deal with both problems:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace Assignment_6_attempt_1

{

///

/// Handles addresses. Street, Zip code, City (3) / Street, zip code, city, and country (4)

///

class Address

{

//declaring variables

//private string m_street; // delete this

//private string m_zipCode; // delete this

//private string m_city; // delete this

//private Assignment_6_attempt_1.ContactFiles.Countries m_country; // delete this

private ContactFiles.Countries Countries;

///

/// Default constructor for calling another constructor in this class.

///

public Address() : this(string.Empty, string.Empty, "Malmo")

{

this.Street = null;

this.ZipCode = null;

this.City = "Malmo";

}

///

/// Constructor with 3 parameters

///

public Address(string street, string zip, string city)

: this(street, zip, city, Assignment_6_attempt_1.ContactFiles.Countries.Sverige)

{

this.Street = street;

this.ZipCode = zip;

this.City = city;

}

///

public Address(string street, string zip, string city, Assignment_6_attempt_1.ContactFiles.Countries country)

{

this.Street = street;

this.ZipCode = zip;

this.City = city;

this.Countries = country;

}

///

/// Properties

///

public string Street { get; set; }

public string City { get; set; }

public string ZipCode { get; set; }

public Assignment_6_attempt_1.ContactFiles.Countries Country { get; set; }

///

/// replaces "_" with space for the country enums

///

public string GetCountryString()

{

string strCountry = Country.ToString(); // changed to property

strCountry = strCountry.Replace("_", " ");

return strCountry;

}

///

/// override the ToString method to return a string made of the address detail

///

public override string ToString()

{

string strOut = string.Format("{0, -25) {1,-8} {2, -10} {3}", Street, ZipCode, City, GetCountryString()); // changed to properties here

return strOut;

}

public string GetAddressLabel()

{

string strOut = Street + ZipCode + City + Country;

return strOut;

}

public bool Validate()

{

if (Street != null) // changed to property

{

return true;

}

return false;

}

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Vulpes11y ago
When you create an object of a class, all its fields (i.e. class level variables) are automatically given their defaults values unless they've been initialized to something else.

The default values are zero for numbers, false for bool, '\0' for char and null for all reference types including strings.

You'll get a compiler warning if you fail to assign a definite value to a field though this is only a warning and the program will still compile (and hopefully run) if you don't do anything about it.

However, I think you have a more serious problem here in that the m_street, m_zipcode, m_city and m_country are duplicating the Street, Zipcode, City and Country 'automatic' properties.

When you have automatic properties, the compiler generates the backing fields automatically so you don't need to do this yourself.

I'd therefore remove the declaration of the 'm_' fields and change them to the properties when they're accessed in the executable code. This should hopefully deal with both problems:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Assignment_6_attempt_1
{
///
/// Handles addresses. Street, Zip code, City (3) / Street, zip code, city, and country (4)
///
class Address
{
//declaring variables
//private string m_street; // delete this
//private string m_zipCode; // delete this
//private string m_city; // delete this
//private Assignment_6_attempt_1.ContactFiles.Countries m_country; // delete this
private ContactFiles.Countries Countries;


///
/// Default constructor for calling another constructor in this class.
///
public Address() : this(string.Empty, string.Empty, "Malmo")
{
this.Street = null;
this.ZipCode = null;
this.City = "Malmo";

}
///
/// Constructor with 3 parameters
///
///
///
///
public Address(string street, string zip, string city)
: this(street, zip, city, Assignment_6_attempt_1.ContactFiles.Countries.Sverige)
{
this.Street = street;
this.ZipCode = zip;
this.City = city;
}

///
///
///
///
///
///
///
public Address(string street, string zip, string city, Assignment_6_attempt_1.ContactFiles.Countries country)
{
this.Street = street;
this.ZipCode = zip;
this.City = city;
this.Countries = country;

}
///
/// Properties
///
public string Street { get; set; }
public string City { get; set; }
public string ZipCode { get; set; }
public Assignment_6_attempt_1.ContactFiles.Countries Country { get; set; }


///
/// replaces "_" with space for the country enums
///
///
public string GetCountryString()
{
string strCountry = Country.ToString(); // changed to property
strCountry = strCountry.Replace("_", " ");
return strCountry;

}
///
/// override the ToString method to return a string made of the address detail
///
///
public override string ToString()
{
string strOut = string.Format("{0, -25) {1,-8} {2, -10} {3}", Street, ZipCode, City, GetCountryString()); // changed to properties here
return strOut;

}

public string GetAddressLabel()
{
string strOut = Street + ZipCode + City + Country;
return strOut;

}
public bool Validate()
{
if (Street != null) // changed to property
{
return true;
}
return false;

}

}
}