从对象键构建字符串

const obj = {
  name: 'Alice',
  age: 30,
  city: 'New York'
};

// 方法一：简单键值对字符串
const keyValueString = Object.entries(obj).map(([key, value]) => `${key}:${value}`).join(',');
console.log(keyValueString); // 输出: name:Alice,age:30,city:New York

// 方法二：键列表字符串
const keyListString = Object.keys(obj).join(',');
console.log(keyListString); // 输出: name,age,city

// 方法三：JSON字符串
const jsonString = JSON.stringify(obj);
console.log(jsonString); // 输出: {"name":"Alice","age":30,"city":"New York"}

const sortedKeys = Object.keys(obj).sort();
const sortedKeyValueString = sortedKeys.map(key => `${key}:${obj[key]}`).join(',');
console.log(sortedKeyValueString); // 输出: age:30,city:New York,name:Alice

const encodedKeyValueString = Object.entries(obj).map(([key, value]) => `${encodeURIComponent(key)}:${encodeURIComponent(value)}`).join(',');
console.log(encodedKeyValue.jsString); // 输出: name%3AAlice%2Cage%3A30%2Ccity%3ANew%20York