If you're asking for a example you'd be more likely to use, JSON is a pretty good example. The GSON interface [0] has isArray()/getAsJsonArray(), isObject()/get

If you're asking for a example you'd be more likely to use, JSON is a pretty good example. The GSON interface [0] has isArray()/getAsJsonArray(), isObject()/getAsJsonObject(), etc. for determining the type of an element, but this isn't type-safe. Pattern matching is a more convenient way to work with raw JSON: public int countNodes(JsonElement el) { return switch(el) { case JsonObject obj -> obj.entrySet().stream() .mapToInt(e -> countNodes(e.getValue())).sum() case JsonArray arr -> arr.stream().mapToInt(::countNodes).sum() default -> 1 } } [0] https://www.javadoc.io/doc/com.google.code.gson/gson/latest/com.google.gson/com/google/gson/JsonElement.html https://www.javadoc.io/doc/com.google.code.gson/gson/latest/...