js判断数据是否为json

function isJSON(str) {
  try {
    JSON.parse(str);
  } catch (e) {
    return false;
  }
  return true;
}

// 示例
console.log(isJSON('{"name":"John", "age":30, "city":"New York"}')); // 输出: true
console.log(isJSON('This is not JSON')); // 输出: false

function isJSON(str) {
  const jsonRegex = /^[\],:{}\s]*$/;
  return (jsonRegex.test(str.replace(/\\["\\\/bfnrtu]/g, '@').
      replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']').
      replace(/(?:^|:|,)(?:\s*\[)+/g, '')));
}

// 示例
console.log(isJSON('{"name":"John", "age":30, "city":"New York"}')); // 输出: true
console.log(isJSON('This is not JSON')); // 输出: false