C# how to check if var contains constructor Params

December 6, 2021

using System;

namespace Exercise_7
{
    public class Dog
    {
        public string Name;
        public string Sex;
        public string Father;
        public string Mother;

        public Dog(string name, string sex)
        {
            Name = name;
            Sex = sex;
        }

        public Dog(string name, string sex, string father, string mother)
        {
            Father = father;
            Mother = mother;
            Name = name;
            Sex = sex;
        }

       public string DogsOverall()
        {
            return $"Name {Name}, sex{Sex}, fathers name is {Father}, mothers name is {Mother}";
        }

Basically, there is some vars that does not contain Father or Mother, so how can i check that? or like how to i print instead of nothing – "unknown"?

>Solution :

You can call the second constructor from your first one and pass in "unknown" for example.

You can also use the ?? operator to use a fallback value when/if father/mother is null.

namespace Exercise_7
{
    public class Dog
    {
        public string Name;
        public string Sex;
        public string Father;
        public string Mother;

        public Dog(string name, string sex) : this(name, sex, "unknown", "unknown")
        {
        }

        public Dog(string name, string sex, string father, string mother)
        {
            Father = father ?? "unknown";
            Mother = mother ?? "unknown";
            Name = name;
            Sex = sex;
        }

   public string DogsOverall()
    {
        return $"Name {Name}, sex{Sex}, fathers name is {Father}, mothers name is {Mother}";
    }