Parse your first JSON

The public learning entry point is FMS. Give it a JSON-like string and call parse().

import com.ajaxjs.jsonparser.syntax.FMS;
import java.util.List;
import java.util.Map;

String text = "{name: 'Ada', active: true, scores: [95, 88]}";
Object result = new FMS(text).parse();

Map<String, Object> person = (Map<String, Object>) result;
System.out.println(person.get("name"));       // Ada
System.out.println(person.get("active"));     // true

List<Object> scores = (List<Object>) person.get("scores");
System.out.println(scores.get(0));             // 95

The cast is necessary because parse() can return several kinds of values. Check the root value before casting when you do not control the input.

What Java values are returned?

Objects and arrays may be nested. Each nested object is another Map; each nested array is another List.

Standard JSON versus this learning parser

Standard JSON requires double-quoted keys and strings:

{"name":"Ada","active":true}

aj-json also accepts the easier-to-type form below because it is useful for observing the lexer, but it is not portable JSON:

{name: 'Ada', active: true}

When learning, try both forms and inspect the tokens. In a real API, always emit and expect standard JSON, then use a mature JSON library to handle it.

Errors are part of the lesson

Malformed input usually throws JsonParseException. Its message includes a character, line, and column position to help you find where the parser became confused.

try {
    new FMS("{name: }").parse();
} catch (RuntimeException e) {
    System.out.println(e.getMessage());
}

This example is for learning how syntax errors surface. Do not use exception messages as a stable production interface.

Next, see how the parser works.