JAVASCRIPT

get value of selected checkbox jquery

$('#checkbox_id:checked').val();
//if checkbox is selected than gets its value

jquery get checked checkbox values array

let weekdays = $('input[name="weekday"]:checked').map(function () {
  return $(this).val()
}).get()

jQuery get values of selected checkboxes

$('input[name="checkboxGroup"]:checked');  // returns checked input objects

jquery get selected checkbox value array

$("#merge_button").click(function(event){
    event.preventDefault();
    var searchIDs = $("#find-table input:checkbox:checked").map(function(){
      return $(this).val();
    }).get(); // <----
    console.log(searchIDs);
});

jquery find checkbox by value

$(":checkbox[value=4]").prop("checked","true");