Handling null/empty/undefined values in JavaScript

Javascript code to check if a given value is null,empty, or undefined using util library.

var is_empty = function (_value) {
  if (typeof _value === "undefined" || _value === null) {
    return true;
  } else if (util.isString(_value) && (_value.trim() === "" || _value.length === 0)) {
    return true;
  } else if (util.isArray(_value) && _value.length === 0) {
    return true;
  } else if (util.isObject(_value)) {
    for (var key in _value) {
      if (_value.hasOwnProperty(key)) {
        return false;
      }
    }
    return true;
  }
  return false;
};