I am looking for the most efficient way to loop over multiple array of objects and add values to a set.

// This is how filesData object looks

const filesData : 
{
hashedEmail: "liugdfkjn83i",
name: "JohnSimith"
}

const setOfHashedEmails = new Set<string>();

    for (const filesData of objectDataInS3Folder) {

// filesData is an array of objects

      // Loop over the array of objects and add only the hashedItem to a set
      filesData.forEach(element=> setOfHashedEmails.add(element.hashedEmail));
    }

Is there a better way to loop over the array of objects multiple times and add the hashedEmail to the set (by using spread operator)

Other possible way can be:

    const arrayOfAllUsers = [];
    for (const filesData of objectDataInS3Folder) {
      arrayOfAllUsers.concat(filesData);
    }

    // Create a set of hashed emails
    const setOfHashedEmails = new Set<string>(arrayOfAllUsers.map(item => item.HashedEmail));