8ee50178f3
Correct: `Array.from()` (it’s a static method) Incorrect: `Array.join()` (doesn’t exist; it’s a prototype method) This patch uses the common `#` syntax to denote `.prototype.`.
20 lines
691 B
Markdown
20 lines
691 B
Markdown
### bind
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Creates a function that invokes `fn` with a given context, optionally adding any additional supplied parameters to the beginning of the arguments.
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Return a `function` that uses `Function.prototype.apply()` to apply the given `context` to `fn`.
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Use `Array.prototype.concat()` to prepend any additional supplied parameters to the arguments.
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```js
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const bind = (fn, context, ...boundArgs) => (...args) => fn.apply(context, [...boundArgs, ...args]);
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```
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```js
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function greet(greeting, punctuation) {
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return greeting + ' ' + this.user + punctuation;
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}
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const freddy = { user: 'fred' };
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const freddyBound = bind(greet, freddy);
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console.log(freddyBound('hi', '!')); // 'hi fred!'
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```
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