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30-seconds-of-code/snippets/flip.md
Angelos Chalaris 611729214a Snippet format update
To match the starter (for the migration)
2019-08-13 10:29:12 +03:00

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---
title: flip
tags: adapter,function,intermediate
---
Flip takes a function as an argument, then makes the first argument the last.
Return a closure that takes variadic inputs, and splices the last argument to make it the first argument before applying the rest.
```js
const flip = fn => (first, ...rest) => fn(...rest, first);
```
```js
let a = { name: 'John Smith' };
let b = {};
const mergeFrom = flip(Object.assign);
let mergePerson = mergeFrom.bind(null, a);
mergePerson(b); // == b
b = {};
Object.assign(b, a); // == b
```