Cannot read property 'username' of undefined in mongoose - node.js

Question

I want to access user object inside of the for loop but I get the error.
User.find({resume :{$ne : null}}, (err,user)=>{
if(err) res.send('ther is some problem for updating resumes') ;
if(user){
for(var i = 0 ; i < user.length ; i++){
Like.count({for : user[i].username }, (err,count)=>{
if(err) res.send('there is something wrong with counting likes');
console.log('inside: ' + user[i].username);
})
}
}
})
user.js
var mongoose = require('mongoose') ;
var schema = mongoose.Schema({
username : {
type : String,
require : true
},
password : {
type : String,
require : true ,
},
resume : {
type : String
},
date : {
type : Date,
default : Date.now()
}
})
module.exports= mongoose.model("user",schema) ;
I can't firgure out what is wrong !

Answer 1

Try this:
User.find({ resume: { $ne: null } }, (err, users) => {
if (err) res.send('there is some problem for updating resumes');
//for debugging, temporarily log number of users found...
console.log(`${users.length} were found with no resume!`);
if (users.length > 0) {
users.forEach((user) => {
Like.count({ for: user.username }, (err, count) => {
if (err) res.send('there is something wrong with counting likes');
console.log('inside: ' + user.username);
})
});
}
});
Pointers
users is an array, you cannot check for falsy on array with if (array), because empty arrays are truthy. So check the length if (array.length > 0.
this wasn't your problem, but it's safer to use native array methods than your own for loops., e.g. users.forEach... instead of for (var i = 0; ....