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.`.
18 lines
479 B
Markdown
18 lines
479 B
Markdown
### composeRight
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Performs left-to-right function composition.
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Use `Array.prototype.reduce()` to perform left-to-right function composition.
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The first (leftmost) function can accept one or more arguments; the remaining functions must be unary.
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```js
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const composeRight = (...fns) => fns.reduce((f, g) => (...args) => g(f(...args)));
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```
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```js
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const add = (x, y) => x + y;
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const square = x => x * x;
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const addAndSquare = composeRight(add, square);
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addAndSquare(1, 2); // 9
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```
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