const mergeSort = (arr1, arr2) => { if (arr1.length === 0) { return arr2; } if (arr2.length === 0) { return arr1; } const mergedArry = []; let i = 0; let j = 0; while (i < arr1.length && j < arr2.length) { if (arr1[i] < arr2[j]) { mergedArry.push(arr1[i]); i++; } else { mergedArry.push(arr2[j]); j++; } } return [...mergedArry, ...arr1.slice(i), ...arr2.slice(j)] }; console.log(mergeSort([0,3,4], [5, 6, 35]));