How can you identify a sign change in a JavaScript array?

Question

How can you identify a sign change in a JavaScript array?

I'm working with a JavaScript array and need some help. The array looks something like this:

var exampleArr1 = [5,4,1,-2,-5,-7,5,1,2,-3,2,4...];
var exampleArr2 = [-5,-4,1,2,5,7,-5,1,2,3,-2,4...];

My goal is to create a function that can detect sign changes in the array and return the position along with the numbers involved in the change. So, the output should look like ['index','num1','num2'] as shown in the example below.

function getSignChange(exampleArr1){
 ...
 return someArray;
}

The expected output should be:

[
  [2,1,-2],  //index = 2 change from 1 to -2
  [5,-7,5],  //index = 5 change from -7 to 5
  [8,2,-3],  //index = 8 change from 2 to -3
]

If anyone has any advice or guidance on how to achieve this, it would be greatly appreciated. Thank you!

javascript arrays

Answer 1

Answer №1

Perhaps this solution can guide you:

var dataArr1 = [5,4,1,-2,-5,-7,5,1,2,-3,2,4];
var dataArr2 = [-5,-4,1,2,5,7,-5,1,2,3,-2,4];

function findSignChange(arr){
 let positive = arr[0] >= 0;
 return arr.map((element, index) => {
  if (positive && element < 0 || !positive && element >= 0) {
    positive = arr[index] >= 0
    return [index-1, arr[index-1], element]
  }  
 }).filter(x => x != null);
}

console.log(findSignChange(dataArr1));
console.log(findSignChange(dataArr2));

Answer 2

Perhaps this solution can guide you:

var dataArr1 = [5,4,1,-2,-5,-7,5,1,2,-3,2,4];
var dataArr2 = [-5,-4,1,2,5,7,-5,1,2,3,-2,4];

function findSignChange(arr){
 let positive = arr[0] >= 0;
 return arr.map((element, index) => {
  if (positive && element < 0 || !positive && element >= 0) {
    positive = arr[index] >= 0
    return [index-1, arr[index-1], element]
  }  
 }).filter(x => x != null);
}

console.log(findSignChange(dataArr1));
console.log(findSignChange(dataArr2));

How can you identify a sign change in a JavaScript array?

Answer №1

Similar questions

Adding Hash to Array: final Hash replaces existing array elements

Implementing JavaScript from dojo.xhrGet within a Symfony framework

Improving an HTML list with JavaScript

Tips on displaying five bootstrap modal popups simultaneously on a webpage

Only when the tab is refreshed will React Query be shown

Ways to prevent users from selecting dates that are over a year from the present date in a datetime-local TextField

The React Reducer is yielding an undefined result

How can one determine the completion of a chunked download request in Angular's HTTP client?

Issue with gulp-uglifyjs arising from an empty return by gulp.src

What is the best way to ensure that the input submit element is only visible after the input checkbox element has been checked?

Can node.js be used to extract slides from PowerPoint and convert them into images?

Gather data from a variety of HTML5 video seminars

Navigating the Path: Strategies for Caching Server-side Rendering in Next Js

How can I remove a row from a JavaScript array based on the value of the first item in the row?

The width of Material UI Grid decreases every time it is re-rendered

What is the best way to transfer variables between PHP and an external JavaScript file?

The middleware attached to the router using router.use is not being executed

Enhancing wordpress custom fields using ajax without overwriting them

Steps for recreating a Jquery Mobile form element with the same name after destroying it

Place the image on the canvas