drilling down in a set of nested objects in JavaScript

Question

I have 4 objects nested within each other. I am trying to change the value of the "chk" property in the inner most object of all the records. Each object has a variable number of properties.

The basic structure is like this

    EMPLOYEE NAME
      JOB#
        PHASE
           CODE
             DAYSoFwEEK
             CHK

I was trying to use some for in loops to get there like this

this.chkEmp = function(e)
{
   /*e is an event listener which is triggered by a click on one of the check boxes.  the id is the value of the outer most object*/
   var i = e.target.id;

    /*loop through jobs
      this is where I get in trouble j is the job which is an object
      so I think "this.recs[i][j]" is not a proper reference
    */
    for ( var j in this.recs[i] )
    {
        /*loop through phase codes*/
        for ( var p in this.recs[i][j] )
        {
            for ( var c in this.recs[i][j][p] )
            {
                this.recs[i][j][p][c].chk = e.target.checked;
            }               
        }
    }
};

How can I loop through all the data and change the value of chk from true to false?

Here is some sample data

"Last_Name, First_Name" Object { 85109={...},  85665={...},  85762={...}}
    85109   Object { 60={...}}
    85665   Object { 60={...}}
        60 Object { 1={...},  3={...}}
            1  Object { 0=0,  1=0,  2=0,  more...}
                0 0
                1 0
                2 0
                3 2.75
                4 0
                5 0
                6 0
                chk true
            3  Object { 0=0,  1=0,  2=0,  more...}
    85762   Object { 60={...}}
        60 Object { H={...}}
            H  Object { 0=0,  1=10.5,  2=10.75,  more...}
                0 0
                1 10.5
                2 10.75
                3 5.75
                4 0
                5 0
                6 0
                chk true

Answer 1

Now I finally understand why my original code did not work. In addition to updating the nested objects, I also wanted to turn off some related check boxes.

In the code below the variables "jobs", "phase" and "code" are a reference to the objects

whereas "j", "p", "c" are the names of the objects.

so i really needed both, one to reach the name of the document control (checkbox) and the other to reference the nested object so I could loop it.

    this.chkEmp = function(e)
{
    var i = e.target.id;
    var recs = this.recs[i];
    var jobs, phase, code;

    for (var j in recs) {
        jobs = recs[j];
        /*loop through phase codes*/
        for (var p in jobs) {
            phase = jobs[p];
            for (var c in phase) {
                code = phase[c];
                code.chk = e.target.checked;
                if (document.getElementById(i+"~"+j+'~'+p+'~'+c))
                {
                    document.getElementById(i+"~"+j+'~'+p+'~'+c).checked  = e.target.checked;
                }
            }
        }
    }
};

Answer 2

Re-writing as follows (with more meaningful variable names) should make the program easier to reason about.

this.chkEmp = function (e) {
    /*e is an event listener which is triggered by a click on one of the check boxes.  the id is the value of the outer most object*/
    var i = e.target.id;

    /*loop through jobs
      this is where I get in trouble j is the job which is an object
      so I think "this.recs[i][j]" is not a proper reference
    */
    var recs = this.recs[i];
    var recsJ, recsJp, recsJpc;

    for (var j in recs) {
        recsJ = recs[j];
        /*loop through phase codes*/
        for (var p in recsJ) {
            recsJp = recsJ[p];
            for (var c in recsJp) {
                recsJpc = recsJp[c];
                recsJpc.chk = e.target.checked;
            }
        }
    }
};