List<T> class

NOTE: For 2.0 the #constructor argument has changed. List now optionally accepts a collection, and only checks types in TypeScript.

An ordered iterable collection. In TypeScript it is a generic class that enforces at compile-time the type of elements that may be added to the List.

An example usage:

  var list = new go.List();  // or in TypeScript: new go.List<go.Point>();
  list.add(new go.Point(0, 0));
  list.add(new go.Point(20, 10));
  list.add(new go.Point(10, 20));
  // now list.length === 3
  // and list.elt(1) instanceof go.Point

You can iterate over the items in a List:

  var it = aList.iterator;
  while (it.next()) {
    console.log("#" + it.key + " is " + it.value);
  }

Or:

  aList.each(val => {
    console.log(val);
  });

The key will range from zero to #count-1.

For convenience this GoJS List class has synonyms for the following methods and property:

  • get(idx): #elt
  • set(idx,val): #setElt
  • has(val): #contains
  • delete(val): #remove
  • clear(): #clear
  • size: #count

The constructor now takes an optional Iterable or Array argument that provides the initial elements for the new List.

Note that GoJS iteration is quite different than ES6 iteration, so that functionality has not been made somewhat compatible. These collection classes were defined in GoJS before the ES6 collection classes were proposed.

Implemented types
Available extensions
Annotations
  • @JS()
  • @staticInterop

Constructors

List.new([Object? coll])
factory

Properties

count → num

Available on Iterable<T>, provided by the Iterable$Typings extension

This read-only property is the number of elements in the collection.
no setter
count ↔ num

Available on List<T>, provided by the List$Typings extension

This read-only property is the length of the List.
getter/setter pair
first ↔ T? Function()

Available on Iterable<T>, provided by the Iterable$Typings extension

getter/setter pair
hashCode → int
The hash code for this object.
no setterinherited
iterator ↔ Iterator<T>

Available on Iterable<T>, provided by the Iterable$Typings extension

Gets an Iterator that can iterate over the items in the collection.
getter/setter pair
iterator ↔ Iterator<T>

Available on List<T>, provided by the List$Typings extension

Gets an object that you can use for iterating over the List. The key will be an integer from zero to the count-1. The value will be the item at that index in the list. Typical usage:
getter/setter pair
iteratorBackwards ↔ Iterator<T>

Available on List<T>, provided by the List$Typings extension

Gets an object that you can use for iterating over the List in backwards order. The key will be an integer from count-1 to zero. The value will be the item at that index in the list. The list is not modified by traversing in reverse order. Typical usage:
getter/setter pair
length ↔ num

Available on List<T>, provided by the List$Typings extension

This read-only property is the length of the List, a synonym for the #count property.
getter/setter pair
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
size ↔ num

Available on List<T>, provided by the List$Typings extension

This read-only property is the length of the List.
getter/setter pair

Methods

add(T val) → List<T>

Available on List<T>, provided by the List$Typings extension

Adds a given value to the end of the List.
addAll(Object coll) → List<T>

Available on List<T>, provided by the List$Typings extension

Adds all of the values of a collection to the end of this List.
all(bool pred(T)) → bool

Available on List<T>, provided by the List$Typings extension

This is true if all invocations of the given predicate on items in the collection are true.
any(bool pred(T)) → bool

Available on List<T>, provided by the List$Typings extension

This is true if any invocation of the given predicate on items in the collection is true.
clear() → void

Available on List<T>, provided by the List$Typings extension

Clears the List. This sets the #count to zero.
contains(T val) → bool

Available on List<T>, provided by the List$Typings extension

Returns whether the given value is in this List. @param {T} val The value to check. @return {boolean} Whether or not the value is contained within the List.
copy() → List<T>

Available on List<T>, provided by the List$Typings extension

Makes a shallow copy of this List. The values are not copied, so if they are objects they may continue to be shared with the original List. @expose @return {List.
delete(T val) → bool

Available on List<T>, provided by the List$Typings extension

Removes a given value (if found) from the List.
each(void func(T)) → List<T>

Available on List<T>, provided by the List$Typings extension

Call the given function on each item in the collection. @expose @param {function(T)} func This function must not modify the collection. @return {List.
elt(num i) → T

Available on List<T>, provided by the List$Typings extension

Returns the element at the given index. @param {number} i int The index of the element to return. @return {T} the value at the given index.
filter(bool pred(T)) → List<T>

Available on List<T>, provided by the List$Typings extension

Call the given predicate on each item in the collection and for each item that it returns true, collect the item in a new List.
first() → T?

Available on List<T>, provided by the List$Typings extension

Returns the first item in the list, or null if there is none. @return {T|null} This returns null if there are no items in the list.
get(num i) → T

Available on List<T>, provided by the List$Typings extension

Returns the element at the given index. @param {number} i int The index of the element to return. @return {T} the value at the given index.
has(T val) → bool

Available on List<T>, provided by the List$Typings extension

Returns whether the given value is in this List. @param {T} val The value to check. @return {boolean} Whether or not the value is contained within the List.
indexOf(T val) → num

Available on List<T>, provided by the List$Typings extension

Returns the index of the given value if it is in this List. @param {T} val The value to check. @return {number} int returns -1 if the value is not in this list.
insertAt(num i, T val) → void

Available on List<T>, provided by the List$Typings extension

Insert a value before the index i.
last() → T?

Available on List<T>, provided by the List$Typings extension

Returns the last item in the list, or null if these is none. @return {T|null} This returns null if there are no items in the list. @since 1.5
map<S>(S func(T)) → List<S>

Available on List<T>, provided by the List$Typings extension

Call the given function on each item in the collection and collect the results in a new List.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
pop() → T?

Available on List<T>, provided by the List$Typings extension

Returns the last item in the list and removes it from the list, or just return null if these is none. Use #add to push an item onto the end of the list. Use #last to get the last item without reducing the length of the list. @return {T|null} This returns null if there are no items in the list. @since 1.5
push(T val) → void

Available on List<T>, provided by the List$Typings extension

Adds a given value to the end of the List.
remove(T val) → bool

Available on List<T>, provided by the List$Typings extension

Removes a given value (if found) from the List.
removeAt(num i) → void

Available on List<T>, provided by the List$Typings extension

Removes a value at a given index from the List.
removeRange(num from, num to) → List<T>

Available on List<T>, provided by the List$Typings extension

Removes a range of values from the List, given both the starting and the ending zero-based indexes. For example,
reverse() → List<T>

Available on List<T>, provided by the List$Typings extension

Reverse the order of items in this List. @return {List.
set(num i, T val) → void

Available on List<T>, provided by the List$Typings extension

Set the element at the given index to a given value. @param {number} i int The index of the element to set. @param {T} val The value to set at the index.
setElt(num i, T val) → void

Available on List<T>, provided by the List$Typings extension

Set the element at the given index to a given value. @param {number} i int The index of the element to set. @param {T} val The value to set at the index.
sort(num sortfunc(T, T)) → List<T>

Available on List<T>, provided by the List$Typings extension

Sort the List according to a comparison function. @param {function(T,T):number} sortfunc This function is passed two items in the list. It should return zero if they are equal, less than zero if the first value should come before the second value, or greater than zero if the first value should come after the second value. @return {List.
sortRange(num sortfunc(T, T), [num? from, num? to]) → List<T>

Available on List<T>, provided by the List$Typings extension

(undocumented) Sorts a range of consecutive elements in this List based on the given comparison function. @param {function(,):number} sortfunc This function is passed two elements in the list. It should return zero if they are equal, less than zero if the first value should come before the second value, or greater than zero if the first value should come after the second value. @param {number=} from int The optional index at which to start the sort, including that element; default to zero, the first element of the list. @param {number=} to int The optional index at which to end the sort, excluding that element; defaults to the end of the list. @return {List.
toArray() → Array<T>

Available on List<T>, provided by the List$Typings extension

Produces a JavaScript Array from the contents of this List. @return {Array.
toSet() → Set<T>

Available on List<T>, provided by the List$Typings extension

Converts the List to a Set. The count of the resulting Set may be less than the count of this List if any duplicates were removed. @return {Set.
toString() → String
A string representation of this object.
inherited
toString$() → String

Available on List<T>, provided by the List$Typings extension

@return {string}

Operators

operator ==(Object other) → bool
The equality operator.
inherited