Getting a random element from a list

For certain applications such as games, it is necessary to have a means to retrieve a random element from a collection in Dart. This recipe will show you a simple way to do this.

How to do it...

This is easy to do; refer to the random_list.dart file:

import 'dart:math';

Random rnd = new Random();
var lst = ['Bill','Joe','Jennifer','Louis','Samantha'];

void main() {
  var element = lst[rnd.nextInt(lst.length)];
  print(element); // e.g. 'Louis'
  element = randomListItem(lst);
  print(element); // e.g. 'Samantha'
}

How it works...

We generate a random index number based on the list length and use it to retrieve a random element from the list. If you need this often, use the one-line function randomListItem for it, as shown in the following code:

randomListItem(List lst) => lst[rnd.nextInt(lst.length)];

See also

  • Consult the previous recipe for more information about the use of Random
..................Content has been hidden....................

You can't read the all page of ebook, please click here login for view all page.
Reset