I have JSON data like this -
var json = {
"details": [
{
"A": {
"Name": "mike",
"Age": 22
},
"B": {
"Name": "John",
"Age": 25
}
}
]
}
I want to read A,B points as an array.
Another way to do it with your json, Object.keys(),since your options are not in array form, can use that to convert to array form.
var json = {
"details": [
{
"A": {
"Name": "mike",
"Age": 22
},
"B": {
"Name": "John",
"Age": 25
}
}
]
}
var outputDiv = document.getElementById('output');
var options = Object.keys(json.details[0]).map(function(item){
return '<option value="'+item+'">'+ item +'</option>'
})
options.unshift('<option value="" > Please select </option>')
var select = document.getElementById('your_options');
select.innerHTML = options.join()
select.onchange = function() {
outputDiv.innerHTML = JSON.stringify(json.details[0][this.value]);
}
<label>You options</label>
<select id="your_options">
</select>
<div id="output"></div>
Lets assume you receive the following JSON from a web server
'{ "firstName":"Foo", "lastName":"Bar" }'
To access this data you first need to parse the raw JSON and form a Javascript object
let response = JSON.parse('{ "firstName":"Foo", "lastName":"Bar" }');
This forms an object which we can access relativly simply
let firstName = response["firstName"];
let lastName = response["lastName"];
Have a look at javascript documentation regarding JSON:
http://devdocs.io/javascript-json/
Examples:
JSON.parse('{}'); // {}
JSON.parse('true'); // true
JSON.parse('"foo"'); // "foo"
JSON.parse('[1, 5, "false"]'); // [1, 5, "false"]
JSON.parse('null'); // null
Related
I want to convert a text file to JSON, but in a very particular way. My text file looks like this:
Data 1:
datapoint1-1 = 21
datapoint1-2 = 23
Data 2:
datapoint2-1 = 21
datapoint2-2 = 23
datapoint2-3 = 23
I want to create a JSON file that separates this data like this:
{
{
"Data": "1",
"Datapoints": [
{
"datapoint1-1": "21",
"datapoint1-2": "23"
}
]
},
{
"Data": "2",
"Datapoints": [
{
"datapoint2-1": "21",
"datapoint2-2": "23",
"datapoint2-3": "23"
}
]
}
}
My first step has split the data into 2 arrays inside an array. The first array is Data 1 plus its data-points and the second is Data 2 plus its data-points.
Now I am stuck on how I can convert those arrays into the JSON format I want. Does anyone have an idea? or can direct me in the right direction for this?
Thanks,
Here is my solution
const input = `
Data 1:
datapoint1-1 = 21
datapoint1-2 = 23
Data 2:
datapoint2-1 = 21
datapoint2-2 = 23
datapoint2-3 = 23
`
const array = input.split('\n').reverse()
const response = []
let template = {}
template['Datapoints'] = []
let switcher = false
array.map(arr => {
// remove empty strings
if (arr) {
if (arr.includes('datapoint')) {
const keyValue = arr.split(' = ')
template.Datapoints.push({ [`${keyValue[0]}`]: keyValue[1] })
} else {
const keyValue = arr.split(' ')
template.Datapoints.reverse()
template[keyValue[0]] = keyValue[1].slice(0, -1)
switcher = true
}
if (switcher) {
response.push(template)
template = {}
template['Datapoints'] = []
switcher = false
}
}
})
const finalResponse = response.reverse()
console.log(JSON.stringify(finalResponse, null, 2))
and in console you got
[
{
"Datapoints": [
{
"datapoint1-1": "21"
},
{
"datapoint1-2": "23"
}
],
"Data": "1"
},
{
"Datapoints": [
{
"datapoint2-1": "21"
},
{
"datapoint2-2": "23"
},
{
"datapoint2-3": "23"
}
],
"Data": "2"
}
]
To convert text files in JSON you can use the JACKSON OBJECT MAPPER jar in your code. Create a simple POJO. It will read JSON string from a file and map it to your class.
Then you would need to convert the JSON string value to java object. This will help you with the same.
I have data from backend in my js like this:
var list = {
"6": {
"id": 6,
"name": "John",
"age": 31
},
"42": {
"id": 42,
"name": "Alex",
"age": 25
},
"3": {
"id": 3,
"name": "Tim",
"age": 58
},
};
Then I need to display this data in my angular html template through ngFor directive. But first I have to get an array of object keys:
var listKeys= Object.keys(list);
Next I can output data in template:
<div *ngFor="let item of listKeys">
<p>{{list[item].id}}</p>
<p>{{list[item].name}}</p>
<p>{{list[item].age}}</p>
<hr>
</div>
But the problem is that order of my data changed. I have in listKeys next array ["3", "6", "42"]. But I want to have original order in that one ["6", "42", "3"]. One of solutions that I have found is make keys as not numeric string. For example:
var list = {
"+6": {...},
"+42": {...},
"+3": {...},
};
But I don't have access to backend. I need another solution.
P.S. The way in which I get data from the backend
getData() {
this._dataService.getList(this.name, this.age).subscribe(res => {
this.list = JSON.parse(JSON.stringify(res));
this.listKeys = Object.keys(this.list);
});
}
By definition, an object is an unordered collection of properties. As a solution, you could use an array instead of an object:
The first step would be to convert the response from the server to an array in the same order.
// Original JSON string received from API
var jsonString = `{
"6": {
"id": 6,
"name": "John",
"age": 31
},
"42": {
"id": 42,
"name": "Alex",
"age": 25
},
"3": {
"id": 3,
"name": "Tim",
"age": 58
}
}`;
// Array of ordered id's
const orderedIds = [];
// Find all id's in the JSON string and push them to the array
const pattern = /"?id"?\: (\d*)/g;
let match;
while (match = pattern.exec(jsonString)) {
orderedIds.push(parseInt(match[1]));
}
// parse the original JSON object
const originalList = JSON.parse(jsonString);
// resulting ordered Array
const result = [];
// Push the object in the array by order
for(x of orderedIds) {
result.push(originalList[x]);
}
// Log the resulting array
document.getElementById("result").innerText = JSON.stringify(result);
<pre id="result"></pre>
The result will be an array of the objects in the same order as they appeared in the JSON string:
result = [
{
"id": 6,
"name": "John",
"age": 31
},
{
"id": 42,
"name": "Alex",
"age": 25
},
{
"id": 3,
"name": "Tim",
"age": 58
},
];
After this you can use it in your template:
<div *ngFor="let item of result">
<p>{{item.id}}</p>
<p>{{item.name}}</p>
<p>{{item.age}}</p>
<hr>
</div>
this array does garantee the order of its values.
This is bound to have edge cases, but adding it because it works
If you are getting the data from the backend in the form of JSON then you can do the following
note: var json is a placeholder, as you haven't shown HOW you get your data
var json = `{
"6": {
"id": 6,
"name": "John",
"age": 31
},
"42": {
"id": 42,
"name": "Alex",
"age": 25
},
"3": {
"id": 3,
"name": "Tim",
"age": 58
}
}`;
var result = JSON.parse(json.replace(/\s?"(\d+)":/g, '"$1 ":'));
console.log(Object.keys(result));
Again, this is bound to fail, but I can't see any other way you can "fix" this on the client side - I thought JSON.parse "reviver" function would help, but it gets the properties in 3, 6, 42 order as well - so, no use at all
I'm trying to access members in a json, however I am running into some trouble. Here is an example of one of the json objects, stored in var obj:
var fs = require('fs');
var obj = [
{
"_id": "52d7f816f96d7f6f31fbb680",
"regNum": "0361300035313000002",
"sd": "2013-01-01T00:00:00",
"pd": "2013-01-25T09:30:29Z",
"prd": "2012-12-18",
"p": 1395000000,
"pt": [
{
"name": name here",
"price": 1395000000,
"OKDP": {
"code": "5520109",
"name": "name here"
},
"sid": "25484812",
"sum": "1395000000",
"OKEI": {
"code": "796",
"name": "name two"
},
"quantity": "1"
}
],
"b": 0,
"c": 0,
"s": 0
}
];
I'm trying to access the sid and sum values, by doing the following:
var sid = [];
var sum = [];
obj.forEach(block => {
var sidOut = block.pt.sid;
var sumOut = block.pt.sum;
sid.push(sidOut);
sum.push(sumOut);
});
console.log(sid);
console.log(sum);
I tried the solution here, however, when I run these it gives me [ undefined ] errors.
Why am I unable to access this two values?
if you see your pt is an array of an object [{}] so you need to select which element you want to access so
var sidOut = block.pt[0].sid;
var sumOut = block.pt[0].sum;
should get you the right result
The url has following json data:
[{ "topic": "cricket",
"value": "Player [ playerid=123, category=b, high=150, total=2300]",
"place": "xyz"},
{ "topic": "cricket",
"value": "Player [ playerid=456, category=c, high=60, total=300]",
"place": "abc"},
{ "topic": "cricket",
"value": "Player [ playerid=789, category=a, high=178, total=5300]",
"place": "bnm"}]
I tried online to check whether this is valid json or not through following link: http://jsonformatter.curiousconcept.com/ it says valid. if it is, how do I access each playerid ?
It is valid JSON, but the data about the player is embedded in a random string. You can do one of two things:
Update the service to send back a different, valid JS value, for example:
"value": {
"type": "Player",
"playerid": 123,
"category": "b",
"high": 150,
"total": 2300
}
Parse the data in the value key yourself:
// Simple regex, not really "parsing"
var playerIdRE = /playerid=(\d+)/i;
var result = playerIdRE.exec(yourData[0].value);
// result[0] is the full match, while result[1] is the ID.
// Or the more complicated version that does full parsing
var format = /\s*(.*?)\s*\[\s*([^\]]+)\s*\]\s*/gi,
keyValuePair = /(\w+)=([^,\]]*),?\s*/gi
function parseComplexDataType(input) {
var result = format.exec(input),
typeName = result[1],
keyValues = result[2],
returnValue = {};
if (!typeName) return returnValue;
returnValue.typeName = typeName;
input.replace(keyValuePair, function(_, key, value) {
returnValue[key] = value;
});
return returnValue;
}
// Usage:
> parseComplexDataType("Player [ playerid=123, category=b, high=150, total=2300]")
Object {typeName: "Player", playerid: "123", category: "b", high: "150", total: "2300"}
For your purposes, it is not valid. Once the JSON is corrected, you simply need to loop through the array and read each value.
var jArray = [{
"topic": "cricket",
"value": {
"type": "Player",
"playerid": 123,
"category": "b",
"high": 150,
"total": 2300
},
"place": "xyz"
}, {
...
}]
To access the JSON data ...
for (var i=0,len=jArray.length; i<len; i++) {
console.log(jArray[i].topic, jArray[i].value.type);
}
Yes, it is. I check it via: http://jsonlint.com/
Extracting "playerid":
Initialise the string to JSONArray.
Iterate over each element in the above array.
Now, from each element extract "value".
Finally, from this string you can get "playerid" by using string methods (see the code below).
Below is the code in Java:
ArrayList<String> player_ids = new ArrayList<String>();
String s = "YOUR STRING";
JSONArray ja = new JSONArray(s);
for(int i =0; i<ja.length(); i++)
{
String value = ja.getJSONObject(i).getString("value");
int start = value.indexOf("=");
int end = value.indexOf(",");
String player_id = value.substring(start+1, end);
player_ids.add(player_id);
}
Hope it helps!!
i'm trying to create a <String, Array()> map from a json object.
Imagine i got this json structure:
[
{
"userId": "123123",
"password": "fafafa",
"age": "21"
},
{
"userId": "321321",
"password": "nana123",
"age": "34"
}
]
The map i want to create would be:
key (string), value (array)
{
"userId": [
"123123",
"321321"
],
"password": [
"fafafa",
"nana123"
],
"age": [
"21",
"34"
]
}
Is it possible to do this? :/
Thanks in advance.
Demo
var json = '[{"userId" : "123123", "password": "fafafa", "age": "21"}, {"userId" : "321321", "password" : "nana123", "age" : "34"}]';
var list = JSON.parse(json);
var output = {};
for(var i=0; i<list.length; i++)
{
for(var key in list[i])
{
if(list[i].hasOwnProperty(key))
{
if(typeof output[key] == 'undefined')
{
output[key] = [];
}
output[key].push(list[i][key]);
}
}
}
document.write(JSON.stringify(output));
Outputs:
{"userId":["123123","321321"],"password":["fafafa","nana123"],"age":["21","34"]}
function mergeAttributes(arr) {
return arr.reduce(function(memo, obj) { // For each object in the input array.
Object.keys(obj).forEach(function(key) { // For each key in the object.
if (!(key in memo)) { memo[key] = []; } // Create an array the first time.
memo[key].push(obj[key]); // Add this property to the reduced object.
});
return memo;
}, {});
}
var json = '[{"userId" : "123123", "password": "fafafa", "age": "21"}, {"userId" : "321321", "password" : "nana123", "age" : "34"}]';
mergeAttributes(JSON.parse(json));
// {
// "userId": ["123123", "321321"],
// "password": ["fafafa", "nana123"],
// "age": ["21", "34"]
// }
Javascript's JSON.stringify will help you to convert any JSON compliant object model into a JSON string.