get and opt methods for accessing the values by name, and put methods for adding or replacing values by name. The values can be any of these types: Boolean, JSONArray, JSONObject, Number, String, or the JSONObject.NULL object. A JSONObject constructor can be used to convert an external form JSON text into an internal form whose values can be retrieved with the get and opt methods, or to convert values into a JSON text using the put and toString methods. A get method returns a value if one can be found, and throws an exception if one cannot be found. An opt method returns a default value instead of throwing an exception, and so is useful for obtaining optional values. The generic get() and opt() methods return an object, which you can cast or query for type. There are also typed get and opt methods that do type checking and type coercion for you. The opt methods differ from the get methods in that they do not throw. Instead, they return a specified value, such as null.
The put methods add or replace values in an object. For example,
myString = new JSONObject().put("JSON", "Hello, World!").toString(); produces the string {"JSON": "Hello, World"}. The texts produced by the toString methods strictly conform to the JSON syntax rules. The constructors are more forgiving in the texts they will accept:
, (comma) may appear just before the closing brace.' (single quote).{ } [ ] / \ : , = ; # and if they do not look like numbers and if they are not the reserved words true, false, or null.= or => as well as by :.; (semicolon) as well as by , (comma).0x- (hex) prefix. | |
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