Find an entry in the Map using a functional condition.
The functional condition to test. Positional arguments are the value, the index of iteration, and the collection being searched.
The value, if found, otherwise undefined
let c = new Collection([["a", "A"], ["b", "B"], ["c", "C"]]);
c.get("a") === c.find(entry => entry === "A"); // true
Filter the Collection, returning an Array of entries which match a functional condition.
The functional condition to test. Positional arguments are the value, the index of iteration, and the collection being filtered.
An Array of matched values
let c = new Collection([["a", "AA"], ["b", "AB"], ["c", "CC"]]);
let hasA = c.filters(entry => entry.slice(0) === "A");
Apply a function to each element of the collection
A function to apply to each element
Array#forEach
let c = new Collection([["a", {active: false}], ["b", {active: false}], ["c", {active: false}]]);
c.forEach(e => e.active = true);
Get an element from the Collection by its key.
The key of the entry to retrieve
Optional options: { Additional options that affect how entries are retrieved
Throw an Error if the requested key does not exist. Default false.
The retrieved entry value, if the key exists, otherwise undefined
let c = new Collection([["a", "Alfred"], ["b", "Bob"], ["c", "Cynthia"]]);
c.get("a"); // "Alfred"
c.get("d"); // undefined
c.get("d", {strict: true}); // throws Error
Get an entry from the Collection by name. Use of this method assumes that the objects stored in the collection have a "name" attribute.
The name of the entry to retrieve
Optional options: { Additional options that affect how entries are retrieved
Throw an Error if the requested name does not exist. Default false.
The retrieved entry value, if one was found, otherwise undefined
let c = new Collection([["a", "Alfred"], ["b", "Bob"], ["c", "Cynthia"]]);
c.getName("Alfred"); // "Alfred"
c.getName("D"); // undefined
c.getName("D", {strict: true}); // throws Error
Transform each element of the Collection into a new form, returning an Array of transformed values
A transformation function applied to each entry value. Positional arguments are the value, the index of iteration, and the collection being mapped.
An Array of transformed values
Reduce the Collection by applying an evaluator function and accumulating entries
A reducer function applied to each entry value. Positional arguments are the accumulator, the value, the index of iteration, and the collection being reduced.
An initial value which accumulates with each iteration
The accumulated result
let c = new Collection([["a", "A"], ["b", "B"], ["c", "C"]]);
let letters = c.reduce((s, l) => {
return s + l;
}, ""); // "ABC"
Test whether a condition is met by some entry in the Collection.
The functional condition to test. Positional arguments are the value, the index of iteration, and the collection being tested.
Was the test condition passed by at least one entry?
A reusable storage concept which blends the functionality of an Array with the efficient key-based lookup of a Map. This concept is reused throughout Foundry VTT where a collection of uniquely identified elements is required.