JAVASCRIPT

select onchange get value jquery

$('#the_id_select').on('change', function() {
  alert( this.value );
});

//or

$("#the_id_select").change(function(){
   alert( this.value );
});

jquery onchange input value

$("input").change(function(){
  alert("The text has been changed.");
});

onchange input jquery

$(document).on("input", "#payedValue", function () {
    var mad = $("#madyoniya").val();
    var payed = $(this).val();
    $("#rest").val(parseFloat(mad) - parseFloat(payed));
    
});

jQuery onchange event

$(".date").datepicker({
    onSelect: function(dateText) {
        console.log("Selected date: " + dateText + "; input's current value: " + this.value);
    }
});