I've never used JSON before so I'm not familiar with its syntax.
At the moment I have multiple arrays containing different pieces of data.
I would like to create one JSON object, that contains the multiple arrays each with several pieces of data.
E.g.
An object called cars, containing multiple arrays each for a different make of car. In each array would be the model of car along with some other types of data e.g. number of doors (doesn't really matter its just a fictional example.)
It would be greatly appreciated if someone explained the syntax with an example.
This question is related to
json
A good book I'm reading: Professional JavaScript for Web Developers by Nicholas C. Zakas 3rd Edition has the following information regarding JSON Syntax:
"JSON Syntax allows the representation of three types of values".
Regarding the one you're interested in, Arrays it says:
"Arrays are represented in JSON using array literal notation from JavaScript. For example, this is an array in JavaScript:
var values = [25, "hi", true];
You can represent this same array in JSON using a similar syntax:
[25, "hi", true]
Note the absence of a variable or a semicolon. Arrays and objects can be used together to represent more complex collections of data, such as:
{
"books":
[
{
"title": "Professional JavaScript",
"authors": [
"Nicholas C. Zakas"
],
"edition": 3,
"year": 2011
},
{
"title": "Professional JavaScript",
"authors": [
"Nicholas C.Zakas"
],
"edition": 2,
"year": 2009
},
{
"title": "Professional Ajax",
"authors": [
"Nicholas C. Zakas",
"Jeremy McPeak",
"Joe Fawcett"
],
"edition": 2,
"year": 2008
}
]
}
This Array contains a number of objects representing books, Each object has several keys, one of which is "authors", which is another array. Objects and arrays are typically top-level parts of a JSON data structure (even though this is not required) and can be used to create a large number of data structures."
To serialize (convert) a JavaScript object into a JSON string you can use the JSON object stringify() method. For the example from Mark Linus answer:
var cars = [{
color: 'gray',
model: '1',
nOfDoors: 4
},
{
color: 'yellow',
model: '2',
nOfDoors: 4
}];
cars is now a JavaScript object. To convert it into a JSON object you could do:
var jsonCars = JSON.stringify(cars);
Which yields:
"[{"color":"gray","model":"1","nOfDoors":4},{"color":"yellow","model":"2","nOfDoors":4}]"
To do the opposite, convert a JSON object into a JavaScript object (this is called parsing), you would use the parse() method. Search for those terms if you need more information... or get the book, it has many examples.
var cars = [
manufacturer: [
{
color: 'gray',
model: '1',
nOfDoors: 4
},
{
color: 'yellow',
model: '2',
nOfDoors: 4
}
]
]
Another example:
[
[
{
"@id":1,
"deviceId":1,
"typeOfDevice":"1",
"state":"1",
"assigned":true
},
{
"@id":2,
"deviceId":3,
"typeOfDevice":"3",
"state":"Excelent",
"assigned":true
},
{
"@id":3,
"deviceId":4,
"typeOfDevice":"júuna",
"state":"Excelent",
"assigned":true
},
{
"@id":4,
"deviceId":5,
"typeOfDevice":"nffjnff",
"state":"Regular",
"assigned":true
},
{
"@id":5,
"deviceId":6,
"typeOfDevice":"44",
"state":"Excelent",
"assigned":true
},
{
"@id":6,
"deviceId":7,
"typeOfDevice":"rr",
"state":"Excelent",
"assigned":true
},
{
"@id":7,
"deviceId":8,
"typeOfDevice":"j",
"state":"Excelent",
"assigned":true
},
{
"@id":8,
"deviceId":9,
"typeOfDevice":"55",
"state":"Excelent",
"assigned":true
},
{
"@id":9,
"deviceId":10,
"typeOfDevice":"5",
"state":"Excelent",
"assigned":true
},
{
"@id":10,
"deviceId":11,
"typeOfDevice":"5",
"state":"Excelent",
"assigned":true
}
],
1
]
$.each(data[0], function(i, item) {
data[0][i].deviceId + data[0][i].typeOfDevice + data[0][i].state + data[0][i].assigned
});
Use http://www.jsoneditoronline.org/ to understand the JSON code better
Using below method pass any value which is any array:
Input parameter: url, like Example: "/node/[any int value of array]/anyKeyWhichInArray" Example: "cars/Nissan/[0]/model"
It can be used for any response:
public String getResponseParameterThroughUrl(Response r, String url) throws JsonProcessingException, IOException {
String value = "";
String[] xpathOrder = url.split("/");
ObjectMapper objectMapper = new ObjectMapper();
String responseData = r.getBody().asString();
JSONObject jsonObject = new JSONObject(responseData);
byte[] jsonData = jsonObject.toString().getBytes();
JsonNode rootNode = objectMapper.readTree(jsonData);
JsonNode node = null;
for(int i=1;i<xpathOrder.length;i++) {
if(node==null)
node = rootNode;
if(xpathOrder[i].contains("[")){
xpathOrder[i] = xpathOrder[i].replace("[", "");
xpathOrder[i] = xpathOrder[i].replace("]", "");
node = node.get(Integer.parseInt(xpathOrder[i]));
}
else
node = node.path(xpathOrder[i]);
}
value = node.asText();
return value;
}
Enclosed in {} represents an object; enclosed in [] represents an array, there can be multiple objects in the array
example object :
{
"brand": "bwm",
"price": 30000
}
{
"brand": "benz",
"price": 50000
}
example array:
[
{
"brand": "bwm",
"price": 30000
},
{
"brand": "benz",
"price": 50000
}
]
In order to use JSON more beautifully, you can go here JSON Viewer do format
Source: Stackoverflow.com