Find the non existing values in an array and inserting them to the array

Question

I have the following array

var array = {"week1":[{"id":1,"name":"x","mark":"20"},{"id":2,"name":"y","mark":"30"}],"week2":[{"id":1,"name":"x","mark":"40"},{"id":2,"name":"y","mark":"60"},{"id":3,"name":"z","mark":"10"}]}

and I also have an array of student Ids as follows

var studentId = ["1","2","3"]

I want to iterate through array and insert the missing student ids into each week and set mark as zero.

var keys = Object.keys(array);
                for(var x =0; x<studentId .length; x++)
                    {
                        var boolFlag = false;
                        for(var i=0; i<keys.length;i++)
                        {
                            for(var j=0; j=array [keys[i]].length; j++ )
                            {

                                if(studentId [x].id == array [keys[i]][j].id)
                                {
                                    boolFlag = true;
                                    break;

                                }
                            }
                        if(!boolFlag )
                            {
                                array [keys[i]].push({id:studentId [x].id, mark:0});
                            }   
                        }
                    }

This works if all the weeks don't contain a studentId completely. But if any of the weeks contain the studentId then this is not inserting the id correctly.What is wrong in my code?

expected result:

var result =   {"week1":[{"id":1,"name":"x","mark":"20"},{"id":2,"name":"y","mark":"30"},{"id":3,"mark":"0"}],"week2":[{"id":1,"name":"x","mark":"40"},{"id":2,"name":"y","mark":"60"},{"id":3,"name":"z","mark":"10"}]}

UPDATE

var studentId = [{id:"1", name:"x"},{id:"2", name:"y"},{id:"3", name:"z"}]

Change this studentId [x].id to studentId[x], this is the way to get string value from array. — Jyothi Babu Araja
– Jyothi Babu Araja, Commented Jul 12, 2019 at 6:01
@JyothiBabuAraja Im sorry. I have wriiten the studentId array in a wrong format. I have updated the question — tharindu
– tharindu, Commented Jul 12, 2019 at 6:08

Slava Utesinov · Accepted Answer · 2019-07-12 06:10:33Z

1

var array = {
  "week1":[
    {"id":1,"name":"x","mark":"20"},
    {"id":2,"name":"y","mark":"30"}
  ],
  "week2":[
    {"id":1,"name":"x","mark":"40"},
    {"id":2,"name":"y","mark":"60"},
    {"id":3,"name":"z","mark":"10"}
  ]
};
var studentId = [
  {id:"1", name:"x"},
  {id:"2", name:"y"},
  {id:"3", name:"z"}
]

for(var week in array){
    for(var stId of studentId){        
        var weekVal = array[week];
        if(!weekVal.filter(function(st){ return st.id == stId.id; })[0])
            weekVal.push({id:stId.id, name: stId.name, mark:"0"});
    }
}

console.log(array);

answered Jul 12, 2019 at 6:10

Slava Utesinov

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