js 修改json

{
  "name": "John",
  "age": 30,
  "city": "New York"
}

// JSON字符串
let jsonString = '{"name":"John","age":30,"city":"New York"}';

// 解析JSON字符串为JavaScript对象
let jsonObj = JSON.parse(jsonString);

// 修改对象的属性
jsonObj.age = 31;
jsonObj.city = "Los Angeles";

// 添加新属性
jsonObj.country = "USA";

// 删除属性
delete jsonObj.name;

// 将修改后的对象转换回JSON字符串
let modifiedJsonString = JSON.stringify(jsonObj);

console.log(modifiedJsonString);
// 输出: {"age":31,"city":"Los Angeles","country":"USA"}

let jsonString = '{"name":"John","age":30,"city":"New York",}'; // 注意这里的逗号是多余的

try {
  let jsonObj = JSON.parse(jsonString);
} catch (e) {
  console.error("JSON解析错误:", e);
}

function stringifySafe(obj, indent = 2) {
  const cache = [];
  const ret = JSON.stringify(obj, function(key, value) {
    if (typeof value === "object" && value !== null) {
      if (cache.includes(value)) {
        // 循环引用
        return "[Circular]";
      }
      cache.push(value);
    }
    return value;
  }, indent);
  cache.length = 0; // 清空缓存
  return ret;
}

let obj = {};
obj.self = obj;

console.log(stringifySafe(obj));
// 输出: {"self":"[Circular]"}