[рони]

Anna_Medvid,

function manipulateObject(obj, func) {
  return func(obj);
};

function func(obj) {
  return Object.keys(obj).reduce(function (previous, key){
    return previous + obj[key];
  }, "");
}

console.log(manipulateObject({x: 1, y: 3, z:2}, func));

/*
function manipulateObject(obj) {
  return Object.values(obj).join("");
};
console.log(manipulateObject({x: 1, y: 3, z:2}));
*/