JSFiddle - React, Tailwind, and code Playground

by Sergio Kagiema

JavaScript

console.clear();

const getTenBeforeOneAfter = (arr = [
  1,2,2,3,5,5,5,48,25,1,51,58,8,53,25,52
]) => {
  
  const numOfIndexesBefore = 10;
  const numOfIndexesAfter = 1;
  const myDayIndex = arr.findIndex( x => x === 58 );
  const currentIndexNum = myDayIndex ? 1 : 0;
  const mySubArr = arr
                    .slice()
                    .splice(
                      myDayIndex - numOfIndexesBefore,
                      numOfIndexesBefore + numOfIndexesAfter + currentIndexNum
                    )
  
  
  return mySubArr;
};

console.log(getTenBeforeOneAfter())