I have some JSON formatted like this:
[
{
"name": "jsonvalue"
}
]
And I want to print it like println!("{:?}", json["name"]);. How do I access a JSON array from a serde_json::Value?
I would like to not have to use more variables to break it down is the point.
You can access an element from a JSON array by the index operator [0]:
let value = json!([{"name":"jsonvalue"}]);
println!("{}", value[0]["name"]);
"jsonvalue"
Note that the index operator will panic if the element doesn't exist, but you can use .get() to handle that case since it returns an Option.
Related
This is my sample JSON
{
"id":"743",
"groupName":"group1",
"transation":{
"101":"success",
"102":"rejected",
"301":"processing"
}
}
Expected Result:
"101"
"102"
"301"
Can anyone please help me to print the above result using XQuery?
I can achieve this through JavaScript, but I need to write in XQuery.
Not knowing how you are reading the JSON document, whether as a doc in the database or parsing a JSON string, below uses xdmp:unquote() to parse a string, but you could instead just read the document from the database with fn:doc() or through cts:search().
Then, you could just XPath to the transation fields and return those node names with the name() function:
let $jsonData := xdmp:unquote('
{
"id":"743",
"groupName":"group1",
"transation":{
"101":"success",
"102":"rejected",
"301":"processing"
}
}')
return
$jsonData/transation/*/name()
How can I parse a JSON response from https://api.twitchinsights.net/v1/bots/online to an array in Go and iterate over every entry?
I dont understand the struct because there are no keys only values...
Can anyone please help and explain how this works?
I've mapped it but then I get something like
map[_total:216 bots:[[anotherttvviewer 67063 1.632071051e+09] [defb 26097 1.632071051e+09] [commanderroot 17531 1.632071048e+09] [apparentlyher 16774 1.63207105e+09]...
But I cant iterate over the map.
Because the API you're working with returns data where it could be a string or a number (in the array of arrays property bots), you'll need to use []interface{} as the type for each element of that array because the empty interface (https://tour.golang.org/methods/14) works for any type at run time.
type response struct {
Bots [][]interface{} `json:"bots"`
Total int `json:"_total"`
}
Then, as you iterate through each item in the slice, you can check its type using reflection.
It would be ideal for the API to return data in a schema where every JSON array element has the same JSON type as every other element in its array. This will be easier to parse, especially using statically typed languages like Go.
For example, the API could return data like:
{
"bots": [
{
"stringProp": "value1",
"numberProps": [
1,
2
]
}
],
"_total": 1
}
Then, you could write a struct representing the API response without using the empty interface:
type bot struct {
StringProp string `json:"stringProp"`
NumberProps []float64 `json:"numberProps"`
}
type response struct {
Bots []bot `json:"bots"`
Total int `json:"_total"`
}
But sometimes you're not in control of the API you're working with, so you need to be willing to parse the data from the response in a more dynamic way. If you do have control of the API, you should consider returning the data this way instead.
I come from a Python Background and recently started programming using TypeScript and Angular2. I want to know how to obtain keys from a JSON object using TypeScript.
I have a response like so:
response.text()
I pass this object to a function
removeMetaData (my_data: string){
//(Various manipulation)...etc
}
i have read that I can call a json() method instead of text(). If I do that, what is the type I should use for my_data?
Then,
If my JSON looks like this:
{
"count": 100,
"next_page": "http://www.test.com/users/?page=2",
"prev_page": "http://www.test.com/users/?page=3",
"results":[
{
"username": "johnny"
},
Etc....
]
How do I parse that?
I've read I might have to use an interface but I don't understand how.
In python it's just response["next_page"] to get the key of a dictionary, then I can assign that value to a variable within the class. That is exactly what I'm trying to achieve within a component.
Thank you.
ADDITION
list() {
this.requestService.get(this.api_path)
.subscribe(
response => this.populate(response.json()),
error => this.response = error.text()
)
}
populate(payload: object) {
this.count = payload.count;
this.next = payload.next;
this.previous = payload.previous;
*payload.results => this.users = payload.results;******
}
Declare an interface which will be used as value object.
export interface IPage
{
count:number;
next_page:string;
prev_page:string;
results:Array<any>;
...
...
}
var my_data:IPage;
Now assign parsed json value to my_data and access all the properties with '.' operator i.e. my_data.count, my_data.results.
Feel free to throw any question.
If I do that, what is the type I should use for my_data?
Its just a javascript object.
As an example if you json looks like:
{
"foo": {
"bar": "bas"
}
}
Then in the parsed json (in variable someObj) the value someObj.foo.bar would be bas 🌹
In go you unmarshal json into a struct. The problem is that I have an api that might change the type of the value of a key from request to request.
For example objects that might be inlined objects like this:
{
"mykey": [
{obj1},
{obj2}
]
}
but also point to objects by keys, like this:
{
"mykey": [
"/obj1/is/at/this/path",
"/obj2/is/at/this/other/path"
]
}
Some objects can be inlined, but others are referenced from multiple locations.
In javascript or python this wouldn't be a problem. Just check the type.
What's the go-idiomatic way to unmarshal and parse these two objects? Is Reflect the only way?
You could unmarshal this JSON to a structure like the following:
type Data struct {
MyKey []interface{} `json:"mykey"`
}
If the JSON includes strings, they will be decoded as strings in the array. If the JSON includes objects, they will be decoded as map[string]interface{} values. You can distinguish between the two using a type switch. Something like this:
for i, v := range data.MyKey {
switch x := v.(type) {
case string:
fmt.Println("Got a string: ", x)
case map[string]interface{}:
fmt.Printf("Got an object: %#v\n", x)
}
}
You can play around with this example here: http://play.golang.org/p/PzwFI2FSav
[
{
"type": "spline",
"name": "W dor\u0119czeniu",
"color": "rgba(128,179,236,1)",
"mystring": 599,
"data": ...
}
]
I am trying to access this json as json['W doręczeniu']['mysting'], and I get no value why is that?
You're trying to access the index "W doręczeniu" but that's not an index it's a value. Also, what you seem to have is an array of JSON objects.
The [ at the start marks the array, the first element of which is your JSON object. The JSON obj begins with the {
You're also trying to use a [ ], but JSON values are accessed with the dot operator.
I'm not sure which index you're actually trying to access, but try something like this:
var x = json[0].mystring;
The value of "W doręczeniu" is not a key, so you cannot use it to get a value. Since your json string is an array you'll have to do json[0].nameto access the first (and only) element in the array, which happens to be the object. Of course, this is assuming json is the variable you store the array into.
var json = [{"type":"spline","name":"W dor\u0119czeniu","color":"rgba(128,179,236,1)","mystring":599}];
console.log(json[0].mystring); //should give you what you want.
EDIT:
To get the last element in a js array, you can simply do this:
console.log( json[json.length -1].mystring ); // same output as the previous example
'length - 1' because js arrays are indexed at 0. There's probably a million and one ways to dynamically get the array element you want, which are out of the scope of this question.