This should work - I refactored your code a little and added filter to the outer scope so that you can update the object depending on the different types. Updatedata now takes a type and a value and sets the object key and value depending on the target.

var filter = { length:0, height:0, capacity:0 };

function updateData(id, value) {

filter[id] = value;

return filter;

}

$('#length, #height, #capacity').change(function (e) {

console.log( updateData(e.target.id, e.target.value) );

});

Length

Height

Capicity

If you want the "live" value, see this Codepen example: https://codepen.io/juanbrujo/pen/uIqaw