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30-seconds-of-code/snippets/bindKey.md
30secondsofcode b643aa805a Travis build: 1389
2018-01-24 12:24:04 +00:00

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### bindKey
Creates a function that invokes the method at a given key of an object, optionally adding any additional supplied parameters to the beginning of the arguments.
Return a `function` that uses `Function.apply()` to bind `context[fn]` to `context`.
Use `Array.concat()` to prepend any additional supplied parameters to the arguments.
```js
const bindKey = (context, fn, ...args) =>
function() {
return context[fn].apply(context, args.concat(...arguments));
};
```
```js
const freddy = {
user: 'fred',
greet: function(greeting, punctuation) {
return greeting + ' ' + this.user + punctuation;
}
};
const freddyBound = bindKey(freddy, 'greet');
console.log(freddyBound('hi', '!')); // 'hi fred!'
```