JAVASCRIPT

stringify

JSON.stringify(value)
JSON.stringify(value, replacer)
JSON.stringify(value, replacer, space)

Javascript stringify with functions

function stringifyWithFunctions(object) {
  return JSON.stringify(object, (key, val) => {
    if (typeof val === 'function') {
      return `(${val})`; // make it a string, surround it by parenthesis to ensure we can revive it as an anonymous function
    }
    return val;
  });
};

function parseWithFunctions(obj) {
  return JSON.parse(obj, (k, v) => {
    if (typeof v === 'string' && v.indexOf('function') >= 0) {
      return eval(v);
    }
    return v;
  });
};

js stringify

// It helps to turn JS object or value into string
// Syntax:
JSON.stringify(value);
JSON.stringify(value, replacer);
JSON.stringify(value, replacer, space);