Develop Reference

Split string using regex expression

I need to split a dynamic string. The string may look like the one below having Code, Name and EffectDate. or it may have only (Code and Name) or (Code and EffectDate) or (Name and EffectDate). You got the point right.
{"Code":{"value":"1"},"Name":{"value":"Entity1"},"EffectDate":{"value":"23/11/2016"}}
to
...
this.data[0].key ='Code'; \\something like this (desired result)
this.data[0].value = '1';
this.data[1].key = 'Name';
this.data[1].value = 'Entity1';
this.data[2].key = 'EffectDate';
this.data[2].value = '23/11/2016';
What i did in my code :
...
filters:string;
data:string[];
...
this.data = this.filters.split("\b(?:(?!value)\w)+[a-zA-Z0-9/]\b");
console.log(this.data);
I used this pattern \b(?:(?!value)\w)+[a-zA-Z0-9/]\b but still couldn't get the desired result. The this.filter always returns only one array with the same string. Any advice would be helpful. Thank you.
Update #1:
I'm using PrimeNg extension for datatable and i get event as a parameter. In that, event.filters returns me a list of filter objects. I cannot send the object to the service, it needs to be in the format to work with the service.

That looks like JSON. What's to stop you from just doing data = JSON.parse(content) and iterating over the key-values using keys(data) for keys and data[i]["value"] for values?
Try something like this:
var data = [];
for(var i in event.filters){
data.push({"key": i, "value": event.filters[i].value});
}

fastest way to filter array of strings in JavaScript

I am working with some xml files stored on S3. I use the xml2js module in Node to parse the xmls and then I extract the strings that have .jpg in them. I was using the filter method and then tried using my own for loop but that didn't shave any time off. Is there any faster way to write this section of the code or is this the fastest way to get it done. Any help appreciated.
using filter method:
//this took 52393ms
var file = JSON.stringify(data);
var arrayOfStrings = file.split('"');
var images = arrayOfStrings.filter(function(str) {
return str.indexOf('.jpg') !== -1;
});
resolve(images);
using for loop:
//this took 52681ms
var file = JSON.stringify(data);
var arrayOfStrings = file.split('"');
var images =[];
for(let i = 0; i < arrayOfStrings.length; i++) {
if(arrayOfStrings[i].indexOf('.jpg') !== -1) {
images.push(arrayOfStrings[i]);
}
}
resolve(images);
data looks like the following after I use file.split('"');
[ '{','rstuv',':{','options',':[{','![alt](CKrgUgiYMflaWnsGZ009.jpg)']];

var file = JSON.stringify(data);
var arrayOfStrings = file.split('"');
Don't do that. If you want to search through data, keep it structured. Stringifying and then searching that string will not only get you a bunch of mistakes (when strings did contain a quote), lots of array elements that are not even proper strings, and is hardly any improvement over just reading in the original XML file as text and directly searching that.
Instead, just iterate (or recurse if necessary) through the data object (see Access / process (nested) objects, arrays or JSON for details), and filter for the strings (and property names?) in those locations where you expect them. This will be a lot faster.

How To Parse A String Of Concatenated JSON In Browser?

I'm using Socket.IO to move data to the browser. The data sent is a stream of JSON objects, and when it arrives at the browser, it becomes one large string of JSON. The problem is, this JSON can't be parsed by JSON.parse() because it's not "real" JSON.
The data structure can be arbitrary so a RegEx might not do the trick. And this current setup is only temporary. Eventually this stream of JSON will be pre-processed server-side so a stream will not need to be sent to the browser, so I'd like to keep the AJAX/Socket.IO setup I have right now instead of switching over to a JSON stream parser like OboeJS.
What can I do to parse this string of concatenated JSON?
For clarity, the JSON will look like this:
{"a":"A"}{"b":"B"}{"c":"C"}
And I'm trying to parse it in such a way that I can access them like:
console.log(Object.a) //A
console.log(Object.b) //B
console.log(Object.c) //C

In your particular case, you could use Array.prototype.reduce to merge all JSON objects into one:
var unstructuredJson = '{"a":"A"}{"b":"B"}{"c":"C"}';
var jsonArray = "[" + unstructuredJson.split("}{").join("},{") + "]";
var objectArray = JSON.parse(jsonArray);
var result = objectArray.reduce(function(result, item) {
Object.keys(item).forEach(function(propertyName) {
result[propertyName] = item[propertyName];
});
return result;
}, {});
document.body.textContent = JSON.stringify(result);
OP said in some comment:
[...] Each JSON might have nested data like {{}{}}{}{}{}
Then, above approach is broken on this case.
My two cents is that you should put some separator character when you stream these JSON objects and life will be easier: you'll be able to split parent objects easily and you'll just need to change split("}{") with the whole separator.
I suggest you that you use some character that will never happen as part of any property value. You can find a control character on this Wikipedia article: Control character

If each substring is valid JSON but the concatenated part isn't, you can turn the string into a valid array literal and use JSON.parse, then you can process each object using Array methods, e.g. forEach:
var s = '{"a":"A"}{"b":"B"}{"c":"C"}';
var obj = JSON.parse('[' + s.replace(/}{/g,'},{') + ']').forEach(function (obj) {
document.write(JSON.stringify(obj) + '<br>');
});
Or if you want it as a single object:
var s = '{"a":"A"}{"b":"B"}{"c":"C"}';
var obj = JSON.parse(s.replace(/}{/g,','));
document.write(JSON.stringify(obj));

You can use JsonParser to parse concatenated json objects:
ObjectMapper mapper = new ObjectMapper();
JsonFactory factory = new JsonFactory(mapper);
JsonParser parser = factory.createParser(YourJsonString);
List<YourObject> YourObjectList = new ArrayList<>();
Iterator<YourObject> iterator = parser.readValuesAs(YourObject.class);
while(iterator.hasNext()) {
YourObject yourObject = iterator.next();
loginSignalsList.add(yourObject);
}

Split the large string {a:'A'}{b:'B'}{c:'C'} and parse them individually

How to convert a string to JSON format?

I was getting list in array form. So at first place i converted array list to string-
var myJsonString = JSON.stringify(result);
myJsonString="[{"productId":"PI_NAME",
"firstName":null,
"lastName":null,
"customer":null
},
{"productId":"PI_NAME",
"firstName":null,
"lastName":null,
"customer":null
}]"
But again i need to convert myJsonString to Json format, What i need to do? I mean i need to replace 1st" and last ", I guess

You need to call parse now.
JSON.parse(myJsonString)

First, if you ever find yourself building a JSON string by concatenating strings, know that this is probably the wrong approach.
I don't really understand how the first line of your code relates to the second, in that you are not doing anything with JSON-encoded string output from result, but instead just overwriting this on the following line.
So, I am going to limit my answer to show how you could better form JSON from an object/array definition like you have. That might look like this:
// build data structure first
// in this example we are using javascript array and object literal notation.
var objArray = [
{
"productId":"PI_NAME",
"firstName":null,
"lastName":null,
"customer":null
},{
"productId":"PI_NAME",
"firstName":null,
"lastName":null,
"customer":null
}
];
// now that your data structure is built, encoded it to JSON
var JsonString = JSON.stringify(objArray);
Now if you want to work with JSON-encoded data, You just do the opposite:
var newObjArray = JSON.parse(JsonString);
These are really the only two commands you should ever use in javascript when encoding/decoding JSON. You should not try to manually build or modify JSON strings, unless you have a very specific reason to do so.

Json associative array accessing in jQuery

I am getting response in below format for every product and in a single call there can be many products. I am trying to access this data via jQuery but I'm not able to access it.
Productdata['someid'] = { "Product Json data"}
I am using below syntax in jQuery but not getting the data. Please suggest.
alert(Productdata['someid']);

Its not going as JSON format .
JSON is a key : value pair format ;
so your Productdata should be in below format:
Productdata = { 'someid' : "Product Json data"}

A Json like this
var data={"name":"somebody"};
To call
return data.name
Or
return data["name"]

The problem here is that JavaScript does not support associative arrays (scroll down to "Associative arrays, no way!"). It has some internal workarounds which make it appear as if it does, but really all it does is just adding the keys as properties.
So you would most likely be able to access it using Productdata.someid = ....
EDIT:
So assuming you have the following JSON string: {"id":"123"} (which is valid JSON), you can use it like this:
var jsonString = '{"id":"123"}';
var parsedJSON = $.parseJSON(jsonString);
var productID = "product_" + parsedJSON.id;
Does this help?
Some useful links: JSON format checker to make sure the JSON is valid.
Unfortunately I wasn't allowed to add more than 2 links, so the jQuery parseJSON function link is still in the comment below.