Create a hidden field in JavaScript

Question

How do you create a hidden field in JavaScript into a particular form ?

Answer 1

You can use this method to create hidden text field with/without form. If you need form just pass form with object status = true.

You can also add multiple hidden fields. Use this way:

CustomizePPT.setHiddenFields( 
    { 
        "hidden" : 
        {
            'fieldinFORM' : 'thisdata201' , 
            'fieldinFORM2' : 'this3' //multiple hidden fields
            .
            .
            .
            .
            .
            'nNoOfFields' : 'nthData'
        },
    "form" : 
    {
        "status" : "true",
        "formID" : "form3"
    } 
} );

var CustomizePPT = new Object();
CustomizePPT.setHiddenFields = function(){ 
    var request = [];
	var container = '';
	console.log(arguments);
	request = arguments[0].hidden;
    console.log(arguments[0].hasOwnProperty('form'));
	if(arguments[0].hasOwnProperty('form') == true)
	{
		if(arguments[0].form.status == 'true'){
			var parent = document.getElementById("container");
			container = document.createElement('form');
			parent.appendChild(container);
			Object.assign(container, {'id':arguments[0].form.formID});
		}
	}
	else{
		 container = document.getElementById("container");
	}
	
	//var container = document.getElementById("container");
	Object.keys(request).forEach(function(elem)
	{
		if($('#'+elem).length <= 0){
			console.log("Hidden Field created");
			var input = document.createElement('input');
			Object.assign(input, {"type" : "text", "id" : elem, "value" : request[elem]});
			container.appendChild(input);
		}else{
			console.log("Hidden Field Exists and value is below" );
			$('#'+elem).val(request[elem]);
		}
	});
};

CustomizePPT.setHiddenFields( { "hidden" : {'fieldinFORM' : 'thisdata201' , 'fieldinFORM2' : 'this3'}, "form" : {"status" : "true","formID" : "form3"} } );
CustomizePPT.setHiddenFields( { "hidden" : {'withoutFORM' : 'thisdata201','withoutFORM2' : 'this2'}});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id='container'>

</div>

Answer 2

var input = document.createElement("input");

input.setAttribute("type", "hidden");

input.setAttribute("name", "name_you_want");

input.setAttribute("value", "value_you_want");

//append to form element that you want .
document.getElementById("chells").appendChild(input);

Answer 3

I've found this to work:

var element1 = document.createElement("input");
element1.type = "hidden";
element1.value = "10";
element1.name = "a";
document.getElementById("chells").appendChild(element1);

Answer 4

You can use jquery for create element on the fly

$('#form').append('<input type="hidden" name="fieldname" value="fieldvalue" />');

or other way

$('<input>').attr({
    type: 'hidden',
    id: 'fieldId',
    name: 'fieldname'
}).appendTo('form')