A JSONArray is an ordered sequence of values. Its external text form is a string wrapped in square brackets with commas separating the values. The internal form is an object having
get
and
opt
methods for accessing the values by index, and
put
methods for adding or replacing values. The values can be any of these types:
Boolean
,
JSONArray
,
JSONObject
,
Number
,
String
, or the
JSONObject.NULL object
.
The constructor can convert a JSON text into a Java object. The toString
method converts to JSON text.
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 coersion for you.
The texts produced by the toString
methods strictly conform to JSON syntax rules. The constructors are more forgiving in the texts they will accept:
- An extra
,
(comma) may appear just before the closing bracket. - The
null
value will be inserted when there is ,
(comma) elision. - Strings may be quoted with
'
(single quote). - Strings do not need to be quoted at all if they do not begin with a quote or single quote, and if they do not contain leading or trailing spaces, and if they do not contain any of these characters:
{ } [ ] / \ : , = ; #
and if they do not look like numbers and if they are not the reserved words true
, false
, or null
. - Values can be separated by
;
(semicolon) as well as by ,
(comma). - Numbers may have the
0-
(octal) or 0x-
(hex) prefix. - Comments written in the slashshlash, slashstar, and hash conventions will be ignored.
@author JSON.org
@version 2008-09-18