31 lines
976 B
Markdown
31 lines
976 B
Markdown
---
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title: Bind object method
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type: snippet
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language: javascript
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tags: [function,object]
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cover: oven-paddle
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excerpt: Creates a function that invokes a method at a key in an object, with optional additional parameters.
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dateModified: 2020-10-18T23:04:45+03:00
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---
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Creates a function that invokes the method at a given key of an object, optionally prepending any additional supplied parameters to the arguments.
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- Return a `function` that uses `Function.prototype.apply()` to bind `context[fn]` to `context`.
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- Use the spread operator (`...`) to prepend any additional supplied parameters to the arguments.
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```js
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const bindKey = (context, fn, ...boundArgs) => (...args) =>
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context[fn].apply(context, [...boundArgs, ...args]);
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```
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```js
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const freddy = {
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user: 'fred',
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greet: function(greeting, punctuation) {
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return greeting + ' ' + this.user + punctuation;
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}
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};
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const freddyBound = bindKey(freddy, 'greet');
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console.log(freddyBound('hi', '!')); // 'hi fred!'
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```
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