Property Procedures vs. Fields

Properties and fields both store and retrieve information in an object. Their similarity can make it difficult to determine which is a better programming choice in a given case.

Use property procedures when:

• You need to control when and how a value is set or retrieved.

• The property has a well-defined set of values that need to be validated.

• Setting the value causes some perceptible change in the object's state, such as an IsVisible property.

• Setting the property causes changes to other internal variables or to the values of other properties.

• A set of steps must be performed before the property can be set or retrieved.

Use fields when:

• The value is of a self-validating type. For example, an error or automatic data conversion occurs if a value other than True or False is assigned to a Boolean variable.

• Any value in the range supported by the data type is valid. This is true of many properties of type Single or Double.

• The property is a String data type, and there is no constraint on the size or value of the string.