30 lines
849 B
Markdown
30 lines
849 B
Markdown
---
|
|
title: cycleGenerator
|
|
tags: function,generator,advanced
|
|
firstSeen: 2020-10-11T17:05:38+03:00
|
|
lastUpdated: 2020-10-11T17:05:38+03:00
|
|
---
|
|
|
|
Creates a generator, looping over the given array indefinitely.
|
|
|
|
- Use a non-terminating `while` loop, that will `yield` a value every time `Generator.prototype.next()` is called.
|
|
- Use the module operator (`%`) with `Array.prototype.length` to get the next value's index and increment the counter after each `yield` statement.
|
|
|
|
```js
|
|
const cycleGenerator = function* (arr) {
|
|
let i = 0;
|
|
while (true) {
|
|
yield arr[i % arr.length];
|
|
i++;
|
|
}
|
|
};
|
|
```
|
|
|
|
```js
|
|
const binaryCycle = cycleGenerator([0, 1]);
|
|
binaryCycle.next(); // { value: 0, done: false }
|
|
binaryCycle.next(); // { value: 1, done: false }
|
|
binaryCycle.next(); // { value: 0, done: false }
|
|
binaryCycle.next(); // { value: 1, done: false }
|
|
```
|