​

myObject = { 'a': 1, 'b': 2, 'c': 3, d: { 'a': 1, 'b': 2, 'c': 3 }}

​

​

    const sqrObjRecursive = (obj) => {

      Object.keys(obj).forEach(key => {

        if (typeof obj[key] === 'object') obj[key] = sqrObjRecursive(obj[key]);

        else obj[key] = obj[key] * obj[key]

      });

      return obj;

    };

​

console.log(sqrObjRecursive(myObject));

​