如果数组中的嵌套数据为空，如何防止出现错误？

const data = {
  users: [
    { name: 'Alice', details: { age: 25 } },
    { name: 'Bob' } // details 属性为空
  ]
};

data.users.forEach(user => {
  if (user.details && user.details.age) {
    console.log(`Name: ${user.name}, Age: ${user.details.age}`);
  } else {
    console.log(`Name: ${user.name}, Age: Not available`);
  }
});

const data = {
  users: [
    { name: 'Alice', details: { age: 25 } },
    { name: 'Bob' } // details 属性为空
  ]
};

data.users.forEach(user => {
  console.log(`Name: ${user.name}, Age: ${user.details?.age ?? 'Not available'}`);
});

const data = {
  users: [
    { name: 'Alice', details: { age: 25 } },
    { name: 'Bob' } // details 属性为空
  ]
};

data.users.forEach(user => {
  const age = user.details?.age ?? 'Not available';
  console.log(`Name: ${user.name}, Age: ${age}`);
});