jquery change value of input

You can apply any one approach:

$("#Input_Id").change(function(){   // 1st
    // do your code here
    // When your element is already rendered
});


$("#Input_Id").on('change', function(){    // 2nd (A)
    // do your code here
    // It will specifically called on change of your element
});

$("body").on('change', '#Input_Id', function(){    // 2nd (B)
    // do your code here
    // It will filter the element "Input_Id" from the "body" and apply "onChange effect" on it
});

$("#textInput").val() // To get value of element textInput

$('selector').val('new value');

    $("button").click(function(){
  $("input:text").val("Glenn Quagmire");
 })

$(selector).val(value)