How does a JSON parser determine whether it is a simple array or object?

The JSON interpreter determines the type of structure based on the first character:

• If the string starts with [ — it is an array. Arrays in JSON are ordered and contain elements without keys.
• If the string starts with { — it is an object. Objects consist of key-value pairs.

Thus, the JSON syntax clearly indicates whether we are dealing with an array or an object, without additional logic.