How to add a ReadOnly property in C#?

Property - A property is an entity that describes the features of an object. A property is a piece of data contained within a class that has an exposed interface for reading/writing. Looking at that definition, you might think you could declare a public variable in a class and call it a property. While this assumption is somewhat valid, the true technical term for a public variable in a class is a field. The key difference between a field and a property is in the inclusion of an interface. We make use of Get and Set keywords while working with properties. We prefix the variables used within this code block with an underscore. Value is a keyword, that holds the value which is being retrieved or set. See code below to set a property as ReadOnly. If a property does not have a set accessor, it becomes a ReadOnly property.

C# Example
public class ClassA
{
private int length = 0;
public ClassA(int propVal)
{
length = propVal;
}
public int length
{
get
{
return length;
}
}
}