Loop over Array inside Loop - arrays

Question

based on this Mongoose embedded documents / DocumentsArrays id
i try to implement a condition in a loop inside a loop. At the end, the new "tosave" Comments Object should contain the _id from the BlogPost based on "where a_id = b_id".
I use node,express and mongoose.
I have a multi row form with multiple BlogPosts and a Blogpost can have multiple Comments.
On the Backend, i have 2 Arrays -> BlogPosts and Comments like this:
BlogPosts: [{ a_id: '1', name: 'name1' },
{ a_id: '2', name: 'name2' },
{ a_id: '3', name: 'name3' }],
Comments: [{ b_id: '1', name: 'comment for BlogPost name1' },
{ b_id: '1', name: 'other comment for BlogPost name1' },
{ b_id: '3', name: 'comment for BlogPost name3' }],
I need the _id from a Blogpost Document inside every Comment, to reference between Comments and Blogposts.
I loop over the BlogPosts like this:
var new_post_to_save = [];
for(var i=0; i<req.body.blogposts.length;i++) {
var newpost = new BlogPost();
console.log('blogpost nr : ' + [i] + ' has new _id: ' + newpost._id );
newpost.name = req.body.blogposts[i].name,
newpost.a_id = req.body.blogposts[i].a_id
new_post_to_save.push(newpost);
},
This is working fine. I get a new Array "new_post_to_save", witch i can save easy.
Now i try to loop inside BlogPosts to give every Comment the _id Field from the new created "newpost" Object.
What i try - but it failed.. It matches all Comments to all BlogPosts.
var new_post_to_save = [];
var new_comment_to_save = [];
for(var i=0; i<req.body.blogposts.length;i++) {
var newpost = new BlogPost();
console.log('blogpost nr : ' + [i] + ' has new _id: ' + newpost._id );
newpost.name = req.body.blogposts[i].name,
newpost.a_id = req.body.blogposts[i].a_id
// here a loop to create x Comments with the _id from newpost and
// the condition: IF a_id = b_id
// then create new Comment and get die _id from his Blogpost
for(var f=0; f<req.body.comments.length;f++) {
if (newpost.a_id = req.body.comments[f].b_id)
console.log(' Yea ! Comment ' + [f] + ' matches Blogpost Nr. ' + [i]);
var newcomment = new CommentModel();
newcomment.id_newpost = newpost._id,
newcomment.name = req.body.comments[f].name,
newcomment.b_id = req.body.comments[f].b_id,
}; // end if
}; // end for
new_comment_to_save.push(newcomment);
new_post_to_save.push(newpost);
}, // end for
This is my first question here.
Any ideas ? Thanks so much

Answer 1

I am not familair with Mongoose, just looking at your code, seems you have a little mistake in code: position of: new_comment_to_save.push(newcomment); it should be in the if because only when they match you want them added..
var new_post_to_save = [];
var new_comment_to_save = [];
for(var i=0; i<req.body.blogposts.length;i++) {
var newpost = new BlogPost();
console.log('blogpost nr : ' + [i] + ' has new _id: ' + newpost._id );
newpost.name = req.body.blogposts[i].name,
newpost.a_id = req.body.blogposts[i].a_id
// here a loop to create x Comments with the _id from newpost and
// the condition: IF a_id = b_id
// then create new Comment and get die _id from his Blogpost
for(var f=0; f<req.body.comments.length;f++) {
if (newpost.a_id = req.body.comments[f].b_id)
console.log(' Yea ! Comment ' + [f] + ' matches Blogpost Nr. ' + [i]);
var newcomment = new CommentModel();
newcomment.id_newpost = newpost._id,
newcomment.name = req.body.comments[f].name,
newcomment.b_id = req.body.comments[f].b_id,
new_comment_to_save.push(newcomment);
}; // end if
}; // end for
new_post_to_save.push(newpost);
}, // end for