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Travis build: 930

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2018-01-03 13:07:44 +00:00
parent d3e8c2f09e
commit 52f3011cd2
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19
snippets/factors.md
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@ -12,24 +12,31 @@ Omit the second argument, `primes`, to return prime and non-prime factors by def
**Note**:- _Negative numbers are not considered prime._
``` js
```js
const factors = (num, primes = false) => {
const isPrime = num => {
const boundary = Math.floor(Math.sqrt(num));
for (var i = 2; i <= boundary; i++) if (num % i === 0) return false;
return num >= 2;
}
};
const isNeg = num < 0;
num = isNeg ? -num : num;
let array = Array.from({length: num - 1}).map((val,i) => num % (i+2) === 0 ? (i+2) : false).filter(val => val);
if(isNeg) array = array.reduce((acc,val) => {acc.push(val); acc.push(-val); return acc}, []);
let array = Array.from({ length: num - 1 })
.map((val, i) => (num % (i + 2) === 0 ? i + 2 : false))
.filter(val => val);
if (isNeg)
array = array.reduce((acc, val) => {
acc.push(val);
acc.push(-val);
return acc;
}, []);
return primes ? array.filter(isPrime) : array;
}
};
```
```js
factors(12); // [2,3,4,6,12]
factors(12,true); // [2,3]
factors(12, true); // [2,3]
factors(-12); // [2, -2, 3, -3, 4, -4, 6, -6, 12, -12]
factors(-12, true); // [2,3]
```