Abstract
You can observe the state of a property with the willSet and didSet keywords. You can use these in the property declaration to assign an action that will occur when a property is about to change and when a property value just changed. Listing 35-1 shows how you would add an action that prints a message to the console log whenever the age property value is about to change and after the age value has changed.
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© 2014 Matthew Campbell
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Campbell, M. (2014). Property Observers. In: Swift Quick Syntax Reference. Apress, Berkeley, CA. https://doi.org/10.1007/978-1-4842-0439-9_35
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DOI: https://doi.org/10.1007/978-1-4842-0439-9_35
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Publisher Name: Apress, Berkeley, CA
Print ISBN: 978-1-4842-0440-5
Online ISBN: 978-1-4842-0439-9
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