Ballerina Playground

play.bal

import ballerina/io;

type Student record {|
    int id;
    string name;
|};
 
public function main() returns error? {
    // As JSON is a union: `()|boolean|int|float|decimal|string|json[]|map<json>`,
    // the following cases are allowed.
    json n = null;
    json i = 21;
    json s = "str";
    json a = [1, 2];
    json m = {"x": n, "y": s, "z": a};
    io:println(m);
    json[] arr = [m, {"x": i}];
    io:println(arr);
 
    string rawData = "{\"id\": 2, \"name\": \"Georgy\"}";
    // Get the `json` value from the string.
    json j = check rawData.fromJsonString();
    io:println(j);
 
    // Access the fields of `j` using field access.
    string name = check j.name;
    io:println(name);
 
    // Convert the `json` into a user-defined type.
    Student student = check j.cloneWithType();
    io:println(student.id);
 
    // Convert the user-defined type to a `json`.
    j = student;
    io:println(j);
}