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Learn Red ? Fundamentals of Red
book

Learn Red ? Fundamentals of Red

by Ivo Balbaert
May 2018
Beginner content levelBeginner
252 pages
6h 19m
English
Packt Publishing
Content preview from Learn Red ? Fundamentals of Red

Looking inside an object

Sometimes, you need to find out whether a certain object has a certain field (or function). The find phrase returns true if the field exists, none if it doesn't:

find person1 'tel         ;== truefind person1 'id-number   ;== none

Again, you have to use the ' literal word syntax. Once you know the field exists, access its value with the familiar path notation, such as person1/tel  ;== "333-4271". However, you could also use select with the same notation:

select person1 'tel          ;== "333-4271"select person1 'id-number    ;== none

Some reflective words exist to get the contents, the list of fields, or the list of the values of an object, as shown in the following snippet:

person1: object [ name: "Mueller" tel: "333-4271" ]body-of ...
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Publisher Resources

ISBN: 9781789130706Supplemental Content