convert json to go struct
Paste the JSON, pick Go and copy the structs with json tags ready. Optional fields get omitempty and a pointer, and nulls become pointers.
id becomes ID; user_name becomes UserName with the original tag.
bio is missing from the second item: pointer with omitempty.
Always present but may be null: pointer without omitempty.
RFC 3339 becomes time.Time and the import is added.
A number and a string in the same field: json.RawMessage.
Fits in int64 without loss, unlike JavaScript.
A field is optional when it is missing from at least one of the objects observed at that position, whether in different documents or in different items of the same array. If every object in a 50-item array has the key phone, it is required; if one does not, it becomes phone?: string. A null value does not make the field optional: it makes it nullable (string | null). The two concepts are different in APIs and in languages, so the tool keeps them apart. The All fields optional switch marks every field optional, which is useful for PATCH bodies and partial responses.
In Go, only identifiers starting with an uppercase letter are exported, and encoding/json ignores unexported fields. The json tag bridges the gap: the ID field reads and writes the key id.
When the value can have different shapes or you want to postpone decoding. The type keeps the original bytes of the value. It is what the tool uses for unions and tuples.
Ids above 2^53 - 1 fit in int64 without loss, unlike JavaScript. If the number exceeds 2^63 - 1, the tool uses uint64 up to 2^64 - 1 and json.Number above that, which keeps the number as text.
Yes. The tags work both ways, Marshal and Unmarshal. With omitempty, zeroed optional fields are no longer written.
export type Root = RootItem[];
export interface RootItem {
id: number;
number: string;
status: string;
createdAt: string;
total: number;
customer: Customer;
items: Item[];
tags: string[];
shipping: Shipping;
billing?: Shipping;
couponCode?: string;
}
export interface Customer {
id: string;
name: string;
email: string;
phone: string | null;
}
export interface Item {
sku: string;
name: string;
qty: number;
price: number;
}
export interface Shipping {
street: string;
city: string;
zip: string;
}
A string with a few repeated values, in at least 8 samples, becomes an enum.
Date-time, date, UUID, email, URL and IPv4.
Objects with the same fields become one type.
Keys that look like ids or dates become a map, and an empty object becomes a map of unknown values.
A fixed-length array with different types per position, like ["a", 1].
Avoids int when the samples happen to contain only integers.
Rejects trailing commas, comments, single quotes and similar.
Language style: camelCase, snake_case or PascalCase, annotated with the original key. Dataclass and TypedDict always keep the keys.
Go, C#, Java, Swift and Pydantic. In other languages the field stays a string.
readonly in TypeScript, frozen in Python, init in C# classes and let in Swift.
The JSON is processed in your browser. Nothing you paste or open is sent to servers.