The tab character ( U+0009), carriage return ( U+000D), line feed ( U+000A), and space ( U+0020) characters are the only valid whitespace characters. Insignificant whitespace may be present anywhere except within a JSONNumber (numbers must contain no whitespace) or JSONString (where it is interpreted as the corresponding character in the string, or would cause an error). String = quotation-mark *char quotation-mark Object = begin-object Īrray = begin-array end-array Value = false / null / true / object / array / number / string Valid JSON syntax is formally defined by the following grammar, expressed in ABNF, and copied from IETF JSON standard (RFC): JSON-text = object / arrayīegin-array = ws %x5B ws [ left square bracketīegin-object = ws %x7B ws right curly bracket For more information, see Object literal syntax vs. The same text may represent different values in JavaScript object literals vs. For those who wish to use a more human-friendly configuration format based on JSON, there is JSON5, used by the Babel compiler, and the more commonly used YAML. Other differences include allowing only double-quoted strings and no support for undefined or comments. Before the revision, U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR are allowed in string literals and property keys in JSON but the same use in JavaScript string literals is a Synta圎rror. NaN and Infinity are unsupported.Īny JSON text is a valid JavaScript expression, but only after the JSON superset revision. A decimal point must be followed by at least one digit. It will act as a disincentive to building single page appsyou’d be able to provide swish transitions without. Property names must be double-quoted strings trailing commas are forbidden. about what a boon the new view transitions API could be for the web: If we get a View Transitions API that works across page navigations, it could potentially turbo-charge the web. It is based upon JavaScript syntax, but is distinct from JavaScript: most of JavaScript is not JSON. OBJECTS If equal, they are left as is Unequal scalar values are replaced by an object containing the old and new value: json-diff.js -full -raw-json <(echo. How do you indicate the deletions? That's just the first example off the top of my head where I don't know how you would want to handle the differences.JSON is a syntax for serializing objects, arrays, numbers, strings, booleans, and null. Consider this simple example: old: ? The "mum" has changed, and the list of "kids" has changed, but has "Mike" changed to "Mary", or are both "Mike" and "Louisa" gone with "Mary" being new, or.? Maybe it should be "kids": because that's the new value. This can be done recursively, and simply return true or false, but a getDifferences(a,b) function is going to get confusing in how it reports the differences within nested objects. If we assume you've already got (parsed) objects, an isEqual(a,b) function really should cope with nested objects, properties that are arrays, etc. Naturally this assumes that your server-side code is creating the JSON strings in a consistent format (and not, e.g., changing the order of the properties). If they are different (or if it is the first request) parse the JSON and process it for display as appropriate. Then when the next response comes in compare the new string with the old string. If you would be happy with a really simple "Has it changed in any way? Yes/No" solution, where if it has changed you just replace the previous object with the new one (as per the part of your question that I quoted), then you could save the JSON response before you parse it, i.e., save it in the string format in which your web-server sends it. Where if there is any changes from one to the other apply them to the stored object or replace it (either way) What I want to do is take the object that was just polled and compare it to a stored one.
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