let user = {

firstName: "san",

lastName: "zhang",

get fullName() {

return this.lastName + this.firstName

},

}

console.log(JSON.stringify(user));

//{"firstName":"san","lastName":"zhang","fullName":"zhangsan"}

/* JSON.stringify 发现参数对象有 toJSON 方法，

就直接使用这个方法的返回值作为参数，而忽略原对象的其他参数 */

let user2 = {

firstName: "san",

lastName: "zhang",

get fullName() {

return this.lastName + this.firstName

},

toJSON: function () {

return {

name: this.lastName + this.firstName

}

}

}

console.log(JSON.stringify(user2)); //{"name":"zhangsan"}

let date = new Date('2022-09-23');

console.log(date.toJSON());

console.log(JSON.stringify(date));

let obj3 = {

reg: /foo/

};

console.log(JSON.stringify(obj3));

RegExp.prototype.toJSON = RegExp.prototype.toString;

console.log(JSON.stringify(/foo/));

JSON.parse(1);

JSON.parse("bar");