Remove null, undefined, NaN, and empty strings from an object.

removeEmptyElements.js

var settings = {
    foo: "",
    bar: undefined,
    hello: "world",
    baz: NaN,
    what: null,
    test: "string",
    zero: 0,
    falseVal: false
}

function removeEmptyElements(object) {
  for (var key in object) {
    var value = object[key];
    if (value === '' ||
        value !== value || /* NaN */
        value == null /* null or undefined */) {
      delete object[key]
    }
  }
}

removeEmptyElements(settings);

console.log(settings) // Returns: Object {hello: "world", test: "string", zero: 0, falseVal: false}

Thanks to @vjeux for shortening the logic a bit!