const justCoolStuff = (arr1, arr2) => arr1.filter(item => arr2.includes(item)); code example

Example: const justCoolStuff = (arr1, arr2) => arr1.filter(item => arr2.includes(item));

**compare two arrays and return a new array with only items present in both arrays:
const justCoolStuff = (arr1, arr2) => arr1.filter(item => arr2.includes(item));