$data = array(
    "name" =>  "王建国",
    "age" => 23
);


echo json_encode($data);
// {"name":"\u738b\u5efa\u56fd","age":23}

echo base64_encode(json_encode($data));
// eyJuYW1lIjoiXHU3MzhiXHU1ZWZhXHU1NmZkIiwiYWdlIjoyM30=

let str = '{"name":"\u738b\u5efa\u56fd","age":23}';

// 正常情况下可以反序列化
console.log(JSON.parse(str));
// { name: '王建国', age: 23 }


// 可能有特殊字符不能解析，可以使用base64解码后再进行json解析
let enstr = "eyJuYW1lIjoiXHU3MzhiXHU1ZWZhXHU1NmZkIiwiYWdlIjoyM30=";

console.log(JSON.parse(atob(enstr)));
// {name: "王建国", age: 23}