Field Vs Property

The normal variable what we declared so far is nothing but Field. Property is somewhat like a field with some differences. The key difference between field and property in C# is that a field is a variable of any type that is declared directly in the class while Property is a member that provides a flexible mechanism to read, write or compute the value of a private field.
Property itself will act like a method so a property cannot be decalred inside a method. We need to declare property directly inside class. Before accepting any value to property we can set certain conditions, only if all those conditions are met then we can assign that value to property. This is not possible in Field.

Syntax
datatype propertyName { get; set;}

In the above syntax, we used keywords called get and set where get is the readable property and it returns a value, set is the writable property where we set conditions. If we want to make a property readonly we can simply remove set; from the property.

NOTE
It is considered good practice to start with Uppercase for properties, as it makes it easier for yourself and others to remember that it is a property and not a field.

CODE

EG 1 . Creating MONTH property

class Program {
    static int month = 1;
    //Property can be elaborated and written as below
    static int Month{
        get {
            return month;
        }
        set {
            //value is the newly assigned value to property.
            if (value < 1 || value > 12) Console.WriteLine("Invalid Month");
            else month = value;
        }
    }

    static void Main(string[] args) {
        Month = 32;
        Console.WriteLine(Month);
        Console.WriteLine();
        Month = 5;
        Console.WriteLine(Month);
    }
}

OUTPUT
Invalid Month
1

5

CODE EXPLANATION
In the above code, we created a property called Month and a field called month. Inside Month property we are having get and set methods. Whenever we try to print property value(Trying to get property value) get method present inside property will be invoked. Whenever we try to assign property value(Trying to set property value) set method present inside property will be invoked. Month value cannot go below 1 and it cannot exceed 12. We set this conditions in the Set method of Month property. Each time when we try to print out Month, the field month value will be returned and printed out in console.

If we try to assign Month value greater than 12 or less than 1 the condition what we set will turn to true so that system will print out Invalid Month and field month value will be still 1 and that will be printed out in console. If we try to set any acceptable value, the condition will turn to false so that field month value will be changed to newly given value. From next time onwards if we try to print out Month value , the newly assigned value will be printed out. In above case, it is 5.


What is the advantage of using property?
Before allowing any changes to property value we can set certain conditions and validate the data, only if all those conditions are met then we can assign that value to property.

Exercises
1. Write DAY property.

(Click Here, For more exercises)