How to filter an array of objects based on another array of object's property value?

Question

I have two sample arrays below.

let arr1 = [
  { key: "WIHUGDYVWJ", className: "science" },
  { key: "qwljdhkuqwdnqwdk", className: "english" },
  { key: "likubqwd", className: "robotics" }
];

let arr2 = [
  { key: "WIHUGDYVWJ", title: "math" },
  { key: "qwljdhkuqwdnqwdk", title: "english" },
  { key: "likubqwd", title: "robotics" }
];

1. How can I filter arr1 to get only items that have 'className' value that matches arr2's item's 'title' value? (expecting only items with 'english' and 'robotics' to remain)

2. How can I filter arr1 to get only items that have 'className' value that do not match arr2's item's 'title' value? (expecting only items with 'science' to remain)

Thanks!