Remove items from one array if not in the second array

Question

I state that I have tried for a long time before writing this post.

For an InDesign script, I\'m working with two array of ListItems. Now I\'m trying to remove the items

Answer 1

arr_A = ["a","b","d","f","g"];
arr_B = ["a","c","f","h"];
var newArr = [];
var item
while ( item = arr_B.shift() ) {
	arr_A.contains ( item ) && newArr[ newArr.length ] = item ;
}
newArr;// ["a", "f"];