node.js json模块

const jsonString = '{"name":"John", "age":30, "city":"New York"}';
const jsonObject = JSON.parse(jsonString);
console.log(jsonObject.name); // 输出: John

const data = {
  name: "John",
  age: 30,
  city: "New York"
};
const jsonString = JSON.stringify(data);
console.log(jsonString); // 输出: {"name":"John","age":30,"city":"New York"}

try {
  const invalidJson = '{"name":"John", "age":}';
  const obj = JSON.parse(invalidJson);
} catch (error) {
  console.error("Invalid JSON:", error);
}

const a = {};
const b = { a };
a.b = b;
try {
  JSON.stringify(a);
} catch (error) {
  console.error("Circular reference:", error);
}

const data = {
  name: "John",
  age: 30,
  sayHello: function() { console.log("Hello!"); }
};
const jsonString = JSON.stringify(data);
console.log(jsonString); // 输出: {"name":"John","age":30}

const jsonStringWithFunctions = JSON.stringify(data, (key, value) => {
  if (typeof value === 'function') {
    return value.toString();
  }
  return value;
});
console.log(jsonStringWithFunctions); // 输出: {"name":"John","age":30,"sayHello":"function() { console.log(\"Hello!\"); }"}