I have a json like this:
a = [{"pk": 1, "model": "gps.test", "fields": {"hi": 23.1, "hello": 47.916142}}]
I want values of pk, hi and hello;
Tried various ways like:
a['pk']
a.pk
None is working. What's wrong?
First, parse your JSON with JSON.parse(json).
a is an array, so grab the first element and then grab the keys from the fields object.
a[0].fields.hi
a[0].fields.hello
If you have more than one object in the array:
a[i].fields.hi
a[i].fields.hello
where i is the index of the element in the array.
Fiddle
a is an array so you need to take at specific index
a[0].pk
Related
First: I'm aware of other solutions like Removing unused information from JSON but I'm looking for a more dynamic approach.
I have two json objects. The first one looks like this:
{
"key2":"value2",
"key3":{
"key4":"value4",
},
"key6":"value6",
}
And the second json objects looks like this:
{
"key1":"value1",
"key2":"value2",
"key3":{
"key4":"value4",
"key5":"value5"
},
"key6":"value6"
}
Is there a dynamic approach (java or javascript) to ensure that only the matching keys between both json objects are returned? In this case, key1 and key5 should be deleted from the second json because this keys are not present in the first one, but the first array does not always look the same.
[{"id":7,"message":"This is another test message","taker_id":"131","giver_id":"102","status":"0","stamp":"2016-08-11"}]
That's my response. I try to get a datum. I have tried data.id but it fails and returns undefined.
As I assume that you are working with a JSON string, you first have to parse the string into and JSON object. Else you couldn't reach any of the properties.
parsedData = JSON.parse(data);
Then you can get your property:
parsedData[0].id
This seems to work just fine
var data = [{
"id":7,
"message":"This is another test message",
"taker_id":"131",
"giver_id":"102",
"status":"0",
"stamp":"2016-08-11"
}];
console.log(data[0].id);
https://jsbin.com/jewatakize/
if you just want to get the id from this one object then data[0].id will work just fine.
If you expect to have multiple objects in that same array then you can use a loop.
for example if this is angular you can do:
<div ng-repeat='info in data'>
<p>{{info.id}}</p>
</div>
This will allow you to iterate through multiple objects within the array and get all id's.
The problem here is that you have here an array of objects, and you are trying to access it without indexing.
You should first parse it using and then access the object by indexing
let objects = JSON.parse(data)
console.log(objects[0].id)
This may be a very simple question but I really can't seem to make it work.
I have several JSON lines and a notes array.
Using notes.push(JSONline) I am saving one JSON line per array position, I assume, so in the following manner:
//notes[1]
{"id":"26","valuee":"20","datee":"2016-04-05T15:15:45.184+0100","id2":51}
//notes[2]
{"id":"27","valuee":"134","datee":"2016-04-05T15:15:47.238+0100","id2":53}
//notes[3]
{"id":"26","valuee":"20","datee":"2016-04-05T15:15:45.184+0100","id2":52}
Here is my problem: I want to print one specific attribute, for example id from one specific JSON line in the array. How can I do this?
When I do console.log(notes) it prints all the JSON lines just as expected. But if I do console.log(notes[1]) it prints the first character of the JSON line in that position, not the whole line.
Similarly console.log(notes[1].id) does not print the id from the first JSON line, in fact it prints 'undefined'.
What am I doing wrong?
Thank you so much.
I'd recommend that you parse all the json when you are pushing to notes, like:
notes.push(JSON.parse(JSONLine))
If you are somehow attached to having json strings in an array instead of objects, which I wouldn't recommend, you could always just parse once you have the jsonLine id
JSON.parse(notes[id]).id
Basically, you want to use JSON.parse for either solution and I'd strongly recommend converting them to objects once at the beginning.
You need to remember that JSON is the string representation of a JS object. JS strings have similar index accessor methods to arrays which is why you can write console.log(notes[0]) and get back the first letter.
JavaScript doesn't allow you to access the string using object notation, however, so console.log(notes[0].id) will not work and the reason you get undefined.
To access the data in the string using this method you need to parse the string to an object first.
var notes = ['{"id":"26","valuee":"20","datee":"2016-04-05T15:15:45.184+0100","id2":51}'];
var note0 = JSON.parse(notes[0]);
var id = note0.id;
DEMO
This leaves the question of why you have an array of JSON strings. While it's not weird or unusual, it might not be the most optimum solution. Instead you could build an array of objects and then stringify the whole data structure to keep it manageable.
var obj0 = {
"id": "26",
"valuee": "20",
"datee": "2016-04-05T15:15:45.184+0100",
id2: 51
};
var obj1 = {
"id": "27",
"valuee": "134",
"datee": "2016-04-05T15:15:47.238+0100",
"id2": 53
}
var arr = [obj0, obj1];
var json = JSON.stringify(arr);
OUTPUT
[
{
"id": "26",
"valuee": "20",
"datee": "2016-04-05T15:15:45.184+0100",
"id2": 51
},
{
"id": "27",
"valuee": "134",
"datee": "2016-04-05T15:15:47.238+0100",
"id2": 53
}
]
You can then parse the JSON back to an array and access it like before:
var notes = JSON.parse(json);
notes[0].id // 26
That's because you have {"id": "value"... as a string in your key value pairs. "id" is a string so you can't reference it like a property. 1. use
var notes = JSON.parse(notes);
as mentioned in the comments by The alpha
or remove the quotes try
{id:"26", ...}
that's why notes[i].id is returning undefined
Is possible that I can preserve the original binded ng-model's data format?
For example, when my original model is:
["tag1", "tag2", "tag3"]
After ng-tag-input's process my model is:
[{"text": "tag1"}, {"text": " tag2"}, {"text": " tag3"}]
I need a way to prevent ng-tag-imput change the format of my model.
Thanks a lot!
ngTagsInput only works with arrays of objects. It will automatically convert an array of strings into an array of objects for convenience.
To convert an array of objects back into an array of strings, you can do the following:
$scope.tagsString = $scope.tags.map(function(tag) { return tag.text; });
I am trying to figure out if I JSON.Stringify an object like this:
{"m_id":"xxx","record":
{"USER":"yyy","PWD","zzz","_createdAt":
11111."_updatedAt":00000},"state":"valid"}
and then try to JSON.Parse out only the USER and PWD, not have to just call the object, but go through stringify. how would that work?
thanks.
I'm not sure why you're talking about stringifying your object. You'd stringify it if you needed to send the data across a network or something, not when you need to manipulate it in JS.
...how do I extract the strings in {...USER: "aaa", PWD: "zzz"...}?
Assuming you have a variable referring to the object, something like the following (with or without nice line breaks and indenting to make it readable, and with or without quotes around the property names):
var obj = {
"m_id": "xxx",
"record": {
"USER": "yyy",
"PWD" : "zzz",
"_createdAt": 11111,
"_updatedAt": 00000
},
"state": "valid"
};
Then you can access the properties in the nested record object as follows:
console.log( obj.record.USER ); // outputs "yyy"
console.log( obj.record.PWD ); // outputs "zzz"
// etc.
(Note: in your question you had two typos, a comma that should've been a colon in between "PWD" and "zzz", and a dot that should've been a comma in between 11111 and "_updatedAt". There's no way that JSON.stringify() would have produced the string that you showed with those mistakes.)
If you want the strings "USER", "PWD" etc as an array, then use Object.keys.
If you want to iterate them, just use a normal for-in enumeration.
I might have misunderstood the question, but if I think it is what it is then try using
var tmp = JSON.parse(string_to_convert)
this should suffice to convert your string to a proper Javascript Object
Then you can do
for(var index in tmp){
console.log(tmp[index]);
}
and this should list all the keys on the first set of properties. If you want to do a nested thing, then use recursion on the properties. Hope this makes sense...