eval typeof is undefined in javascript

Question

I am trying to create JSON object entered into textbox using below code.

colnames is array of columns from table colnames = [DEPTNO,DNAME],

I am trying to create JSON object dynamically. eg

tableInsert.DEPTNO = 100; tableInsert.DNAME= sales;

but when i run it, it always complain console.log (eval ("tableInsert." + col)); is undefined. Any help..

  document.getElementById("insercols").onclick = function(){
    var tableInsert ='';
    var colvalue='';
    console.log("cols are " + colnames);
    for (col of colnames){
        colvalue = document.getElementById(col).value;
        eval ("tableInsert." + col + " = " + "typeof "+  colvalue);

        console.log("tableInsert." + col + " = " + "typeof "+  colvalue);
        console.log (eval ("tableInsert."  + col));

    }
}

Answer 1

define tableinsert as and try again..

var tableInsert = {};
tableInsert[col] = typeof colvalue;