过滤对象数组中的对象键

const data = [
  { id: 1, name: 'Alice', age: 25 },
  { id: 2, name: 'Bob', age: 30 },
  { id: 3, name: 'Charlie', age: 20 }
];

// 基于键值的过滤
const filteredByAge = data.filter(item => item.age > 25);
console.log(filteredByAge); // 输出: [{ id: 2, name: 'Bob', age: 30 }]

// 基于键的存在性过滤
const filteredByName = data.filter(item => item.hasOwnProperty('name'));
console.log(filteredByName); // 输出: [{ id: 1, name: 'Alice', age: 25 }, { id: 2, name: 'Bob', age: 30 }, { id: 3, name: 'Charlie', age: 20 }]

// 基于复杂条件的过滤
const filteredByComplexCondition = data.filter(item => item.age > 20 && item.name.startsWith('A'));
console.log(filteredByComplexCondition); // 输出: [{ id: 1, name: 'Alice', age: 25 }]

const item = { id: 1 };
if (item.hasOwnProperty('name')) {
  console.log(item.name);
} else {
  console.log('Name does not exist');
}

const item = { id: 1, age: '25' };
if (typeof item.age === 'number') {
  console.log(item.age > 20);
} else {
  console.log(Number(item.age) > 20);
}