How to get difference values between an array of values and array of object using lodash

I have two array as

a1 = ['test1@gmail.com','test2@gmail.com','test3@gmail.com'];
a2 = [{email: 'test1@gmail.com'},{email: 'test2@gmail.com'}];

Now I want to get difference between these two array mentioned above as

resultDifference = ['test3@gmail.com'];

How to achieve this difference result by using lodash only.

>Solution :

You should add what you have tried to your post

const a1 = ["test1@gmail.com", "test2@gmail.com", "test3@gmail.com"];
const a2 = [{ email: "test1@gmail.com" }, { email: "test2@gmail.com" }];

const ans = _.difference(
  a1,
  a2.map((a) => a.email)
);