/"removes consecutive elements from anywhere in an array and optionally replace with other elements"/
let arr = ['a1','a2','a3',....]
let replaceArr = ['el1','el2',....]
arr.splice(startIdx,steps,'el1','el2',.....)
// selects startIdx to (startIdx + steps) like slice both inclusive and replaces with el1,el2...
// OR
arr.splice(startIdx,steps,[...replaceArr]) // same using spread
// len(replaceArr) need not be equal to steps, replaceArr is even optional