How to set selected value of jquery select2?

Question

This belong to codes prior to select2 version 4

I have a simple code of select2 that get data from ajax

Answer 1

I think you need the initSelection function

$("#programid").select2({
  placeholder: "Select a Program",
  allowClear: true,
  minimumInputLength: 3,
  ajax: {
    url: "ajax.php",
    dataType: 'json',
    quietMillis: 200,
    data: function (term, page) {
      return {
        term: term, //search term
        flag: 'selectprogram',
        page: page // page number
      };
    },
    results: function (data) {
      return {results: data};
    }
  },
  initSelection: function (element, callback) {
    var id = $(element).val();
    if (id !== "") {
      $.ajax("ajax.php/get_where", {
        data: {programid: id},
        dataType: "json"
      }).done(function (data) {
        $.each(data, function (i, value) {
          callback({"text": value.text, "id": value.id});
        });
        ;
      });
    }
  },
  dropdownCssClass: "bigdrop",
  escapeMarkup: function (m) { return m; }
});