For a oneliner, you could use map from Array.prototype
:
secondArray = secondArray.map((element, index) => firstArray.includes(index) ? "blank" : element )
Please note the map function returns a new array, instead of modifying the original one.
Edit: removed redundant return
and curly-braces around the arrow function body
1
solved how to search for the value with a certain index in an array and modify its value?