I think because in the sum prototype he gives an initial value of 0 in the reduce function. So if an empty array is passed that will be the default value

I think there is an issue in a test of JavaScript, correct me if im wrong.

From this input(8, 300, 400) expected null to deeply equal [ 359, 367] /n
But between 359 and 367 there is 361 that is prime. so... what i am missing? Is the only test of 100 that goes bad

"a" is the array, to know the length of the array to add the correct amounts of "0" - "y" wich is the index

I don't get it, maybe is 'cause my inglish is not to good but i will share my doubts:
In the array of example of the instructions

[
["130/90","140/94"],
["160/110"],
["200/120"],
["150/94","140/90","120/90"],
["140/94","140/90","120/80","130/84"]
] 

it says that # patients at index 0, 2, and 3 are hypertensive;
why at index 3 and not also at index 4? it s because have to be the the last two elements of the array consecutive? I mean the 4th array have 140/94 and 140/90 but the last two tests of hypertension give 120/80 and 130/84 so in conclusion doesn't have hypertension? And if its like i interpret it i have to check only the last two test of the patient and all the other test are noise? I will gladly apreciate an answer. Have a good day/night

how this can be Best Practices?... i mean is clever for sure, but it is really dificult to read

I flatten the array "by hand" and it works so the only problem was that. Maybe because and old version of node or what can may be?

Im in JS, when i run the tests it gives me a message saying: "arr.flat is not a function"... anyone knows why? because i run the same code in other plataform and it work just fine

Its in JavaScript

I have an issue... i run my code on RunJS and there all the test cases pass fine but when i copy the same code and run the test here not passes all of them and with a console.log i see that here it works really weird. How can i do to solve this?

Here in this test case: coinsNeeded(123,[1,2,5,10,20,50]) the console.log shows me that only uses to reduce the amount by 5...
but in my RunJS its reduced properly as shown in the sample test (50+50+20+2+1). I will copy my code here for you to test it in diferrent places but idk if its correct doing that here. So i wait for a response to try to solve my problem. Thank you and have a good day

Why the "+" at the start of the return makes the string into a number? and if i put a "-" instead of the plus symbol makes the negatives go positive and viceversa? I want to know how it works, if someone can explain me or send a link of MDN, i can't find it. Thanks

really nice and clean code, taking notes...

can you resolve this algorithm with only reduce? i used for loops and in cases with 6 digits it crashes. I tried to submit it more than 3 times but there is no case

my code time out only with big numbers but all the other test passes, i should try to do a more efficient algorithm? I wrote it on javascript

I attempt it and passes 105 and failed 3 but i can't see how it looks the ones that failed...
i don't know if its something wrong with my code or is an issue.
A test can bring a face like this: ["~D:"] ? because if it can maybe that it's my issue but it not seems like it because only 3 examples of it.