If you missed the introductory post, it's here. For a list of previously solved katas, please refer to the bottom of this page.
If this is your first time seeing my post, please note - these katas are probably randomly assigned per user so please don't go into Codewars thinking we will have exactly the same user experience, I am just posting these in the order that I got them.
Kata #28
DESCRIPTION:
Given a set of numbers, return the additive inverse of each. Each positive becomes negatives, and the negatives become positives.
invert([1,2,3,4,5]) == [-1,-2,-3,-4,-5]
invert([1,-2,3,-4,5]) == [-1,2,-3,4,-5]
invert([]) == []
You can assume that all values are integers. Do not mutate the input array/list.
Starting code:
function invert(array) {
return ;
}My attempt:
const invert = array => array.map(num=>num*-1)Rank #1 in 'Best Practice':
function invert(array) {
return array.map( x => x === 0 ? x : -x);
}Rank #2:
const invert = array => array.map(num => -num);Rank #3:
function invert(array) {
return array.map(i => 0 - i);
}Rank #4:
function invert(array) {
var newArr = [];
for(var i = 0; i < array.length; i++){
newArr.push(-array[i]);
}
return newArr;
}That's it for Kata #28, stay tuned for more katas to be solved!
Link to Kata #1: Square(n) Sum
Link to Kata #2: Convert a Number to a String
Link to Kata #3: DNA to RNA Conversion
Link to Kata #4: Remove First and Last Character
Link to Kata #5: MakeUpperCase
Link to Kata #6: Total amount of points
Link to Kata #7: A Needle in the Haystack
Link to Kata #8: Sum of positive
Link to Kata #9: Basic Mathematical Operations
Link to Kata #10: Beginner - Reduce but Grow
Link to Kata #11: Square Every Digit
Link to Kata #12: Friend or Foe?
Link to Kata #13: Grasshopper - Summation
Link to Kata #14: Get the Middle Character
Link to Kata #15: Descending Order
Link to Kata #16: String ends with?
Link to Kata #17: Sum of two lowest positive integers
Link to Kata #18: Sum of odd numbers
Link to Kata #19: Find the next perfect square!
Link to Kata #20: Reversed Strings
Link to Kata #21: Jaden Casing Strings
Link to Kata #23: Returning Strings
Link to Kata #24: Opposite number
Link to Kata #25: Are You Playing Banjo?
