24 lines
569 B
Markdown
24 lines
569 B
Markdown
---
|
|
title: flip
|
|
tags: function,intermediate
|
|
---
|
|
|
|
Takes a function as an argument, then makes the first argument the last.
|
|
|
|
- Use argument destructuring and a closure with variadic arguments.
|
|
- Splice the first argument, using the spread operator (`...`), to make it the last 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
|
|
```
|