How we get a single value of mongodb using node js

Question

I have to try to print the value of my MongoDB in the console. But it gives me undefined in my console I had done a lot of things to get the result but all is vain I want to print number single field value (min_score) in console or browser from MongoDB using node.js code

1). This is my node.js code

   this.levelChange = function(req, res, next){

    try{

        var arr = [];
        var query = {'level_num':1};
        QuizLevel.find(query,function(err,data){
            var a = parseInt(arr.push(data));
            console.log(a.min_score);
        });
    }catch(err){
        console.log("Error");
        return next(err);
    }
};
return this;

2). This is my js level schema

   {
     _id:{type:String},
     age:{type:Number},
     level_num:{type:Number},
     min_score:{type:Number},
     max_questions:{type:Number}
     }

3). This is my json value

     {
     "age":5,
      "level_num":1,
     "min_score":10,
     "max_questions":30
     }
    {
     "age":5,
     "level_num":2,
     "min_score":12,
     "max_questions":33
     }
     {
     "age":5,
     "level_num":3,
     "min_score":15,
     "max_questions":35
      }

4). This is the result in console

 [undefind]

I want to get the result min_score 10 in my console

Answer 1

if data is the output like this:

 {
     "age":5,
      "level_num":1,
     "min_score":10,
     "max_questions":30
     }

Then you can simply use data.min_score and output will be: 10

var a = parseInt(arr.push(data)); will gives you the a as 1 so a.min_score will be undefined definitely.

Answer 2

I faced the same problem. Instead of var a = parseInt(arr.push(data)); You need to destructure the array and then use data.min_score

QuizLevel.find(query,function(err,data){
        const [a] = data
        console.log(a.min_score);
    })