const obj = {
  socre: 10,
  skills: { js: 10, react: 20, cpp : 1 }
}

const createScore = (score) => {
  score += 1
  return score
}

const createSkills = (skills) => {
  skills.js += 5
  return skills
}

console.log( obj.score ) // 1. ?
console.log( obj.skills ) // 2. ?

createScore( obj.score )
createSkills( obj.skills )

console.log( obj.score ) // 3. ?
console.log( obj.skills ) // 4. ?