I push an object to my Array in mongoose, array only stores its length - arrays

Question

I try to push an object into an Array in mongoose, but whenever i do it, it puts its length like this(mongoose, the attribute is schoolComment at the bottom), I am using mlab.com for database.
{
"_id": {
"$oid": "58e17ee3e24dfb1f70d76460"
},
"schoolName": "Koc Universitesi",
"schoolIlce": "Sariyer",
"schoolSehir": "Istanbul",
"schoolId": 981299,
"__v": 5,
"schoolComments": [
3
]
}
this is my code in node JS (The comments are not appearing in html because of this reason)
app.post('/comment', function(req, res){
if(req.session.user && req.session){
User.findOne({email: req.session.user.email}, function(err, user){
if(err) {
res.send('error');
}
if(user){
if(req.session.user.password === user.password){
var thisID = user.userid;
Universite.findOne({schoolName: req.body.collegeName}, function(err, college){
if(err) res.send('error');
if(college){
college.set({schoolComments: college.schoolComments.push({thisID: req.body.comment})}).save(function(err){
if(err){
res.render('errors', {error:'Error'});
}else{
res.locals.college = college;
res.locals.user = user;
res.render('universiteinfoUser');
}
});
}
});
}else{
res.render('login', {});
}
}
});
}
});
and this is HTML DOM Form for it. The comments are not appearing because of this reasons.
<form onkeypress="enterPress();" action="/comment" method="post">
<textarea maxlength="100" style="font-size: 25px;" name="comment" rows="3" cols="50" placeholder="Yorumunuzu yazin..."></textarea><br>
<input style="display: none; visibility: hidden;" type="text" name="collegeName" value="<%=college.schoolName%>"></input>
<button type="submit" name="commentSubmit">Comment Submit</button>
</form>
<div class="userCommentDisplay">
<ul>
<%college.schoolComments.forEach(function(item, i){%>
<%var k = college.schoolComments[i]%>
<%for(key in k){%>
<%if(key === user.userid){%>
<li><%=k[key]%> Same</li>
<%}else{%>
<li><%=k[key]%></li>
<%}%>
<%}%>
<%})%>
</ul>
</div>

Answer 1

You may want to use findOneAndUpdate and build your comment item dynamically (to set the dynamic field name) :
var item = {};
item[user.userid] = req.body.comment;
Universite.findOneAndUpdate({
schoolName: req.body.collegeName
}, {
$push: {
"schoolComments": item
}
}, { new: true }, function(err, college) {
if (err) {
res.render('errors', { error: 'Error' });
} else {
res.locals.college = college;
res.locals.user = user;
res.render('universiteinfoUser');
}
});
Note that I've aded { new: true } in order to return the modified document college instead of the unaltered one.
FYI, in your code, you have used JS method Array.prototype.push() that will return the new length of the array by using college.schoolComments.push