I have this code to add key value pair to object

 for (var j = 0; j < words.length; j++) {

      let criteria={};

      let header=headers[j];
      Object.assign(criteria, { header: words[j]} );
  ..

  }

i want to add multiple key value pairs

Object.assign(criteria, { header: words[j]} );

here header is a variable but when i console normal header text is displayed.

the resulting object should look like something like this

{designation : 'Manager',address:'UK',...}

Any solution Thanks