Assigning default values for Class properties

I am wondering about assigning default values for class properties. Is it as symbol as declaring the property and assigning a value:

public var my_property:type = value;

or is it better to declare a private property with the defualt value and then a public property with set to the default value:

private var defaultMy_property:type = value;
public var my_property:type = defaultMy_property;

Any thoughts would be great and thanks in advance.