Duplicate value in javascript array of objects is not recognized by find()

Question

I am making a bookmark function that looks as follows:

  $scope.bookmarkPost = function(bookmark_post){
    if(window.localStorage.bookmarks == null) {
      user_bookmarks = [];
    } else {
      user_bookmarks = JSON.parse(window.localStorage.bookmarks)
    }

    var existing_post = find(user_bookmarks, function(post){ return post.title == bookmark_post.title; });

    if(!existing_post){
      user_bookmarks.push({
        id: bookmark_post.pagid,
        title : bookmark_post.title,
        date: bookmark_post.created,
        room: bookmark_post.room
      });
    }

    console.log(JSON.stringify(user_bookmarks));

    window.localStorage.bookmarks = JSON.stringify(user_bookmarks);
  };

This should work and indeed adds the post to a my array of objects if it allready exists, and then puts it in localstorage. As you can see I'm trying to check if there's allready an entry with the same title like this:

var existing_post = find(user_bookmarks, function(post){ return post.title == bookmark_post.title; });

To be 100% honest I'm not even 100% sure what this does, but I couldn't find anything else on my particular subject. This check doesn't work and thus there are duplicate entries. Does anyone know how it can be fixed?

How are you calling this function (as in, what argument are you passing in?) Where does it get this from? — somethinghere
– somethinghere, Commented Oct 18, 2016 at 15:16
What about user_bookmarks.find(function(post){ return post.title == bookmark_post.title; }); — user3297291
– user3297291, Commented Oct 18, 2016 at 15:27

Oberon · Accepted Answer · 2016-10-18 15:27:37Z

2

You probably meant to use the Array.find() method:

var existing_post = user_bookmarks.find(function(post){ 
  return post.title === bookmark_post.title; //use === for strict comparison
}); //will return only first element that matches the callback criteria

Quick note: Array.find() is not supported by IE

answered Oct 18, 2016 at 15:27

Oberon

2001 silver badge9 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

somethinghere Over a year ago

I was wondering if find is potentially an angular function in this case though... But yeah, this is the way to do it. Also, who cares about IE? :)

Collectives™ on Stack Overflow

Duplicate value in javascript array of objects is not recognized by find()

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related