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Iteration

[Symbol.iterator]()​

extended enum itself is an ES6 iterable. Iteration through the values is possible with for .. of syntax, spread operator, or via similar methods. The values are iterated by its definition order.

enum _Fruit {
  Apple = 'apple',
  Orange = 'orange',
  Pear = 'pear',
  Strawberry = 'strawberry',
}
class Fruit extends extend<typeof _Fruit, _Fruit>(_Fruit) {}

/**
 * Prints:
 * "apple"
 * "orange"
 * "pear"
 * "strawberry"
 */
for (const fruit of Fruit) {
  console.log(fruit.toString());
}

// [Fruit.Apple, Fruit.Orange, Fruit.Pear, Fruit.Strawberry]
const fruits = [...Fruit];

values()​

An alias of [Symbol.iterator()].

// [Fruit.Apple, Fruit.Orange, Fruit.Pear, Fruit.Strawberry]
const fruits = [...Fruit.values()];

keys()​

Returns an ES6 iterable which iterates through the keys of the enum.

// ["Apple", "Orange", "Pear", "Strawberry"]
const fruitKeys = [...Fruit.keys()];

entries()​

Returns an ES6 iterable which iterates through each tuple [key, value] of the enum.

/**
 * [
 *  ["Apple",      Fruit.Apple],
 *  ["Orange",     Fruit.Orange],
 *  ["Pear",       Fruit.Pear],
 *  ["Strawberry", Fruit.Strawberry],
 * ]
 */
const entries = [...Fruit.entries()];