1

As the following test illustrates, if a turtle is running a while when it dies, this breaks out of the while (without any error). Is this behavior guaranteed by NetLogo?

to test
  ca
  let age 0
  crt 1
  ask turtle 0 [
    while [true] [    
      set age (1 + age)
      print (word "age is " age)
      if (random-float 1 < 0.1) [die] ;death ends the while
    ]
  ]
end
Alan
  • 9,410
  • 15
  • 20

1 Answers1

3

Yes- whenever a turtle executes "die" it immediately stops execution of any commands. In your case, the while loop (and "ask turtle 0") is terminated. The turtle is also automatically removed from all agentsets.

If you used "[die show "I'm dead!"]" instead of just "[die]", the code would never show "I'm dead!" because it stops as soon as it executes "die".

(If you have ever tried to program a model that removes agents in another programming language, you should appreciate how magical NetLogo's "die" primitive is. In other languages, doing the same thing can be a complicated nightmare.)

Steve Railsback
  • 1,251
  • 6
  • 7
  • The documentation says an "agent will not execute any further code", but I was not sure this would terminate the while loop rather than possibly raising an error until I tried the provided example. It makes sense that `die` shuts down the 'ask' but I'm still (pleasantly) surprised. – Alan Sep 12 '21 at 12:58