Skip to Content
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

Changing items – poke, replace, and change

There are two ways to change an item in a series. Let's use data: [A B C D], where ABC and D are all words. Suppose we want to replace C with the word X. We can do this as follows:

  • Binding to a path specified by the item index—for example, data/3: 'X   ;== X. Now data has become [A B X D]. Why do we need 'X instead of just X? The reason is that when you're binding to a word, this word is evaluated. So you have to quote the X word in order to prevent evaluation. If you don't do this and use data/3: X, you'd get a Script Error: X has no value.
  • Specifying the item index using poke, such as poke data 3 'X (the position comes first, then the new value).

(To replace C with the string "X" , we just ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

How I Built a Personal Board of Directors With GenAI

How I Built a Personal Board of Directors With GenAI

Vipin Gupta
How to Become a Game-Changing Leader

How to Become a Game-Changing Leader

Douglas A. Ready, Alan Mulally
Why AI Demands a New Breed of Leaders

Why AI Demands a New Breed of Leaders

Faisal Hoque, Thomas Davenport, Erik Nelson

Publisher Resources

ISBN: 9781789130706Supplemental Content