data.IReadOnlyCollection interface

A non-modifiable collection of objects.

Signature:

interface IReadOnlyCollection<V>

Introduced: version 1.0

Type Parameters

Parameter	Type	Description
V	any	The type of the objects in the collection.

Property	Modifiers	Type	Description
size	`readonly`	number	Gets the number of objects in the collection.

Method	Description
[Symbol.iterator]()	Returns an object that can be used to iterate over all objects in the collection.
every(predicate)	Tests whether all objects in the collection satisfy a predicate.
filter(predicate)	Returns a new collection with all objects that satisfy a typeguard.
filter(predicate)	Returns a new collection with all objects that satisfy a predicate.
find(predicate)	Returns the first object in the collection that satisfies a predicate.
firstOrDefault(defaultValue)	Returns the first object in the collection, or a default object if the collection is empty.
includes(v)	Tests whether a collection includes an object.
isEmpty()	Executes firstOrDefault to see if the collection has any elements. If the collection has elements, returns false. Otherwise, returns true.
map(callbackfn)	Returns a new collection populated with the results of calling a function on each object.
reduce(callbackfn, initialValue)	Executes a reducer function on each object in the collection, to reduce it to a single object.
reduceRight(callbackfn, initialValue)	Executes a reducer function on each object in the collection in right-to-left order.
some(predicate)	Tests whether at least one object in the collection satisfies a predicate.
toArray()	Returns a new, read-only array that contains all the objects in the collection.