javascript寻找一种从对象中获取特定键的方法

const obj = { key1: 'value1', key2: 'value2' };
console.log(obj.key1); // 输出: value1

const obj = { key1: 'value1', key2: 'value2' };
const keyName = 'key1';
console.log(obj[keyName]); // 输出: value1

// 使用变量作为键名
const dynamicKey = 'key2';
console.log(obj[dynamicKey]); // 输出: value2

const obj = { key1: 'value1', key2: 'value2' };
const searchKey = (key) => key.startsWith('key');
const foundKey = Object.keys(obj).find(searchKey);
console.log(foundKey); // 输出: key1

const obj = { key1: 'value1', key2: 'value2' };
const searchKeyValue = ([key, value]) => key === 'key1';
const [foundKey, foundValue] = Object.entries(obj).find(searchKeyValue);
console.log(foundKey, foundValue); // 输出: key1 value1

const value = obj.keyThatMayNotExist && obj.keyThatMayNotExist;
// 或者使用可选链
const value = obj?.keyThatMayNotExist;