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30-seconds-of-code/snippets/toPairs.md
2020-09-15 21:52:00 +03:00

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---
title: toPairs
tags: object,array,intermediate
---
Creates an array of key-value pair arrays from an object or other iterable (object, array, string, set etc.).
- Check if `Symbol.iterator` is defined and, if so, use `Array.prototype.entries()` to get an iterator for the given iterable, `Array.from()` to convert the result to an array of key-value pair arrays.
- If `Symbol.iterator` is not defined for `obj`, use `Object.entries()` instead.
```js
const toPairs = obj =>
obj[Symbol.iterator] instanceof Function && obj.entries instanceof Function
? Array.from(obj.entries())
: Object.entries(obj);
```
```js
toPairs({ a: 1, b: 2 }); // [ ['a', 1], ['b', 2] ]
toPairs([2, 4, 8]); // [ [0, 2], [1, 4], [2, 8] ]
toPairs('shy'); // [ ['0', 's'], ['1', 'h'], ['2', 'y'] ]
toPairs(new Set(['a', 'b', 'c', 'a'])); // [ ['a', 'a'], ['b', 'b'], ['c', 'c'] ]
```