Throw an error when the user enter null or empty string

Question

I\'m attempting to resolve the following exercise:

You need to create a class named Product that represents a product. The class has a

Answer 1

If you want different exceptions on null and on empty string (often null means that something is totally wrong, when empty string is just a format error):

public string Name {
  get {
    return name;
  }
  set {
    if (null == value)
      throw new AgrumentNullException("value");
    else if (String.Equals(value, ""))
      throw new AgrumentException("Empty values are not allowed.", "value");

    name = value; 
  }
}

In case you don't want to distiguish them:

public string Name {
  get {
    return name;
  }
  set {
    if (String.IsNullOrEmpty(value))
      throw new AgrumentException("Null or empty values are not allowed.", "value");

    name = value; 
  }
}

Note, that in both cases it's value that you have to test, not a property Name. In your original code the name's (and so Name as well) initial value is null and you'll get exception whatever you try to set.