There are two possible constructors:
new go.Map()
, for JavaScript
new go.Map<K, V>()
for TypeScript
In TypeScript, the two optional generic arguments describe the types of keys and the types of values that this Map may hold.
For example, the expression:
// TypeScript:
new go.Map<string, go.Point>()
produces a Map that has keys that must be strings and whose associated values must be Points.
Optional
coll: Map<K, V> | Iterable<IKeyValuePair<K, V>> | IKeyValuePair<K, V>[]an optional collection of IKeyValuePairs to add, or an Array of IKeyValuePairs.
Readonly
countThis read-only property is the number of associations in the Map.
Readonly
iteratorGets an object that you can use for iterating over the key-value pairs of a Map. Typical usage:
const it = aMap.iterator;
while (it.next()) {
console.log("the key: " + it.key + " has value: " + it.value);
}
Readonly
iteratorGets an object that you can use for iterating over the keys of a Map. Typical usage:
const it = aMap.iteratorKeys;
while (it.next()) {
console.log("key: " + it.value);
}
Readonly
iteratorGets an object that you can use for iterating over the values of a Map. Typical usage:
const it = aMap.iteratorValues;
while (it.next()) {
console.log("value: " + it.value);
}
Readonly
sizeThis read-only property is the number of associations in the Map.
Adds all of the key-value pairs to this Map. If a key is already present in this Map, its value is replaced with the corresponding value from the given map.
Be careful not to call this method while iterating over the collection.
the collection of IKeyValuePairs to add, or an Array of IKeyValuePairs.
This modified Map.
Virtual
allThis is true if all invocations of the given predicate on items in the collection are true.
Call the given predicate on each key/value pair in the collection. As soon as a call returns false, this returns false. Otherwise this returns true. For an empty collection this returns true.
The argument to the predicate will be an IKeyValuePair. This function must not have any side-effects.
True if all predicate calls are true; false otherwise.
Virtual
anyThis is true if any invocation of the given predicate on items in the collection is true.
Call the given predicate on each key/value pair in the collection. As soon as a call returns true, this returns true. Otherwise this returns false. For an empty collection this returns false.
The argument to the predicate will be an IKeyValuePair. This function must not have any side-effects.
True if any predicate call is true; false otherwise.
Clears the Map, removing all key-value associations. This sets the count to zero.
Be careful not to call this method while iterating over the collection.
Virtual
copyVirtual
eachCall the given function on each key/value pair in the collection.
The argument to the function will be an IKeyValuePair. This function must not modify the collection.
This Map itself
Returns the first IKeyValuePair in the collection, or null if there is none.
This returns null if there are no items in the collection.
Return a JavaScript iterator that produces the keys of this Map. This does not produce the old GoJS style Iterator -- use the iteratorKeys property if you want that.
Produces a JavaScript Array of key/value pair objects from the contents of this Map.
A copy of the Map in Array form, each element being an IKeyValuePair
Return a JavaScript iterator that produces the values of this Map. This does not produce the old GoJS style Iterator -- use the iteratorValues property if you want that.
An unordered iterable collection of key/value pairs that cannot contain two instances of the same key. In TypeScript it is a generic class that enforces at compile-time the type of the key and the type of the associated value.
To create a Map:
You can iterate over the key/value pairs in a Map:
Or:
But note that there is no guaranteed ordering amongst the key/value pairs.
Call toKeySet to get a read-only go.Set that holds all of the keys of a Map. Iterating over that Set will produce values that are the keys in the Map.
For compatibility with versions of GoJS before version 3.0, the following synonyms are defined:
The constructor now takes an optional Iterable or Array argument that provides the initial entries for the new Map.
Note that GoJS iteration is quite different than ECMAScript iteration, so that functionality has not been made somewhat compatible. These collection classes were defined in GoJS before the ECMAScript collection classes were proposed.