How to parse special string as JSON?

Question

I have a string as follows:

"{'type': 'name', 'properties': {'name': 'urn:ogc:def:crs:EPSG::3857'}}"

I want to parse this string as JSON.

How can I do that?

Answer 1

The string you are provided is not valid JSON. There are two options either use eval() method or make it valid JSON and parse.

Using eval() method :

var obj = eval('(' + "{'type': 'name', 'properties': {'name': 'urn:ogc:def:crs:EPSG::3857'}}" + ')');

var obj = eval('(' + "{'type': 'name', 'properties': {'name': 'urn:ogc:def:crs:EPSG::3857'}}" + ')');

console.log(obj);

But I don't prefer eval() method, refer : Don't use eval needlessly!

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Or converting it to valid JSON by replacing single quotes with double quotes:

var obj = JSON.parse("{'type': 'name', 'properties': {'name': 'urn:ogc:def:crs:EPSG::3857'}}".replace(/'/g,'"'));

var obj = JSON.parse("{'type': 'name', 'properties': {'name': 'urn:ogc:def:crs:EPSG::3857'}}".replace(/'/g, '"'));

console.log(obj);

FYI : The above code only works when there is no ' (single quote) within property name or value otherwise which replaced by ". For generating JSON in that case you need to use much complex regex.

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But it always better to initialize string itself as a valid JSON and parse it using JSON.parse() method.

{"type": "name", "properties": {"name": "urn:ogc:def:crs:EPSG::3857"}}

var obj = JSON.parse('{"type": "name", "properties": {"name": "urn:ogc:def:crs:EPSG::3857"}}');

console.log(obj);

Answer 2

Try this :

Replace all single quotes (') with double quotes (").

 var s={
        "type": "name",
        "properties": {
            "name": "urn:ogc:def:crs:EPSG::3857"
        }
    }

The JavaScript function JSON.parse(text) can be used to convert a JSON text into a JavaScript object:

 var j=JSON.parse(x);

Now the variable j has the JavaScript object.

Answer 3

Valid JSON would be:

var text = '{"type": "name", "properties": {"name":"urn:ogc:def:crs:EPSG::3857"}}';

var obj = JSON.parse(text);

Answer 4

If you want to avoid eval and want to avoid formatting the string for JSON.parse, you could try:

var jsonStr = "{'type': 'name', 'properties': {'name': 'urn:ogc:def:crs:EPSG::3857'}}";
var jsonFn = new Function("return "+jsonStr);
var json = jsonFn();

Or directly:

var json = (new Function("return {'type': 'name', 'properties': {'name': 'urn:ogc:def:crs:EPSG::3857'}}"))();