Question

I have 3 HTML form inputs fields that is dynamically generated by a “add more” button, with naming for the fields name as fieldName, fieldName1, fieldName2, fieldName3, and so on.

Now, I’m trying to retrieve the value from this fields with JavaScript, using the script below.

var bookingForm = document.forms['formName'];

var qty = bookingForm.fieldName +'i'.value;

with the ‘i’ been a generated numeric number by a for loop
when I use alert(qty), it returns NaN, when I’m expecting the value for fieldName1, fieldName2, and so on.

But when I use;

var qty = bookingForm.fieldName.value

I can get the value in that field but get NaN when I try to concatenate 1,2,3, with the fieldName.

Any help will be very much appreciated.

Answer 1

You use brackets to access a property using a string:

var qty = bookingForm['fieldName' + i].value;