DefineList.extend([name,] [static,] prototype)

Extends DefineList, or constructor functions derived from DefineList, to create a new constructor function.

import DefineList from "can-define/list/list";

const TodoList = DefineList.extend(
    "TodoList",
    {
        "#": { type: { complete: "boolean", name: "string" } },
        availableCount: "number",
        completedCount: {
            get: function() {
                return this.filter( { complete: true } ).length;
            }
        },
        completeAll: function() {
            this.forEach( function( todo ) {
                todo.complete = true;
            } );
        }
    } );

const todos = new TodoList( [
    { name: "dishes", complete: false },
    { name: "lawn", complete: false }
] );
todos.availableCount = 100;

todos.completeAll();
todos.completeCount; //-> 2