22 lines
635 B
Markdown
22 lines
635 B
Markdown
---
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title: accumulate
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tags: math,array,intermediate
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firstSeen: 2020-05-04T12:20:46+03:00
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lastUpdated: 2020-11-03T21:46:13+02:00
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---
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Creates an array of partial sums.
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- Use `Array.prototype.reduce()`, initialized with an empty array accumulator to iterate over `nums`.
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- Use `Array.prototype.slice(-1)`, the spread operator (`...`) and the unary `+` operator to add each value to the accumulator array containing the previous sums.
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```js
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const accumulate = (...nums) =>
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nums.reduce((acc, n) => [...acc, n + +acc.slice(-1)], []);
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```
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```js
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accumulate(1, 2, 3, 4); // [1, 3, 6, 10]
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accumulate(...[1, 2, 3, 4]); // [1, 3, 6, 10]
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```
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