function array_replace_recursive (arr) {
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // *     example 1: array_replace_recursive({'citrus' : ["orange"], 'berries' : ["blackberry", "raspberry"]}, {'citrus' : ['pineapple'], 'berries' : ['blueberry']});
  // *     returns 1: {citrus : ['pineapple'], berries : ['blueberry', 'raspberry']}

  var retObj = {},
    i = 0,
    p = '',
    argl = arguments.length;

  if (argl < 2) {
    throw new Error('There should be at least 2 arguments passed to array_replace_recursive()');
  }

  // Although docs state that the arguments are passed in by reference, it seems they are not altered, but rather the copy that is returned (just guessing), so we make a copy here, instead of acting on arr itself
  for (p in arr) {
    retObj[p] = arr[p];
  }

  for (i = 1; i < argl; i++) {
    for (p in arguments[i]) {
      if (retObj[p] && typeof retObj[p] === 'object') {
        retObj[p] = this.array_replace_recursive(retObj[p], arguments[i][p]);
      } else {
        retObj[p] = arguments[i][p];
      }
    }
  }
  return retObj;
}

array_replace_recursive({'citrus' : ["orange"], 'berries' : ["blackberry", "raspberry"]}, {'citrus' : ['pineapple'], 'berries' : ['blueberry']});

{citrus : ['pineapple'], berries : ['blueberry', 'raspberry']}