Write a javascript code to flatten the given array without using flattened function.

function flattenArray(arr){ let flattened = []; function flatten(ArrElem){ for(let i=0;i<ArrElem.length; i++){ if(Array.isArray(ArrElem[i])){ flatten(ArrElem[i]) } else{ flattened.push(ArrElem[i]) } } } flatten(arr) return flattened } let arr = [1, 2...