View source for Item (Json property)

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This function retrieves of sets an item in a Json array or object, using either the item number for an array or the item (property) name for an object.
==Syntax==
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===Syntax terms===
<table class="syntaxTable">
<tr><th>%currentJson</th><td><var>Json</var> object being retrieved from the object or array.</td></tr>
<tr><th>Json</th>
<td><var>Json</var> object, which must be either an object or array.</td></tr>
<tr><th>index</th>
<td>The number of the item to set or retrieve if the Json object is an array or the name of the item (property) to set or retrieve if the Json object is an object.</td></tr>
<tr><th>newJson</th><td><var>Json</var> object being added to the object or array.</td></tr>
</table>
==Usage notes==
<ul>
<li>As with the [[Item (Arraylist property)|Arraylist Item property]] and the [[Item (Stringlist function)|Stringlist Item function]], the Item method can be invoked implicitly. That is <code>%json:item(%x)</code> is identical to <code>%json(%x)</code>.</li>
<li>JavaScript and JSON terminology refer to the <i>properties</i> of an object. However, the SOUL equivalent of JSON objects, [[NamedArraylist class|NamedArraylists]] use the term <i>items</i> so, since the Json class is a SOUL feature, generally object properties will be referred to as named items.</li>  
<li>If the underlying Json object is an object, the input index is treated as a string, regardless of its datatype.</li>
<li>The names used for objects are always stored internally as unicode so the names can be specified as unicode variables or constants.</li>
<li>If the underlying Json object is an object, specifying a name that is not in the object returns a null on a retrieval and adds the name on a set.</li> 
<li>Unlike NamedArraylists, items are maintained in the object in the order in which they are added &ndash; this is generally the way JavaScript works and, while the JSON standard cautions against depending on property order, it does not forbid it. This does mean that setting and retrieving object items (properties) requires a linear scan of the item list so is not an ideal structure for very large item lists.</li>
<li>If the underlying Json object is an array, the index must specify an item number that is between 1 and the number of items in the array (inclusive) for a retrieval, and between 1 and the number of items in the array plus one (inclusive) for a set. If the item number specified on a set is one more than the number of items in the array, the item is added to the end of the array.</li>
<li>If the underlying Json object is an array, the input index is treated as a number, regardless of its datatype. This means that if it's a string that's not a valid number, it's converted to a 0 which is not a valid item number so results in request cancellation.</li> 
</ul>

==Examples==
The following example sets some object items (properties) by name and then retrieves their values to use in an addition:
<p class="code">b

%json is object json

%json = object
%json('Paris')     = 2243833
%json('Marseille') = 850726
%json('Lyon')      = 484344
%json('Toulouse')  = 441802

printText {~=%json('Paris'):numberValue  + %json('Marseille'):numberValue}
printText {~=%json('Paris'):numberValue  + %json('Lyon'):numberValue}
printText {~=%json('Paris'):numberValue  + %json('Toulouse'):numberValue}

end
</p>
The above prints:
<p class="code">%json('Paris'):numberValue  + %json('Marseille'):numberValue=3094559
%json('Paris'):numberValue  + %json('Lyon'):numberValue=2728177
%json('Paris'):numberValue  + %json('Toulouse'):numberValue=2685635
</p>
The following example replaces the values of some Json array items and then retrieves each item for printing:
<p class="code">b

%json is object json
%i    is float

%json = array(2, 3, 5, 7, 11, 13, 17, 19)
%json(2) = "Berlin"
%json(5) = "Hamburg"
%json(6) = "Munich"

for %i from 1 to %json:count
   printText {%i}: {%json(%i)}
end for

end
</p>
This prints:
<p class="code">1: 2
2: "Berlin"
3: 5
4: 7
5: "Hamburg"
6: "Munich"
7: 17
8: 19
</p>
Of course, if the intent was just to see the contents of the array, the array itself could just be printed, though the format of the output would be slightly different. 
==See also==
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