JSON stringify replacer

gistfile1.js

// @ref: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify#Parameters

function censor(key, value) {
  if (typeof value === "string") {
    return undefined;
  }
  return value;
}

var foo = {
  foundation: "Mozilla",
  model: "box",
  week: 45,
  transport: "car",
  month: 7
};

var jsonString = JSON.stringify(foo, censor);