const prefix = 'user';
const id = 42;
const role = 'admin';

const capitalize = str => str.charAt(0).toUpperCase() + str.slice(1);

const profile = {
  [`${prefix}_${id}`]: 'Marcus',
  [Symbol.iterator]: null,
  [`get${capitalize(role)}`]: () => 'full-access',
  [`${prefix}Count`]: 3,
};

const dynamicKey = `${prefix}_${id}`;

console.log(
  profile[dynamicKey],
  profile[`get${capitalize(role)}`](),
  profile[`${prefix}Count`] * id,
  Object.keys(profile).length
);