What is null in Javascript?

In JavaScript the value null represents the intentional absence of any object value. The value null is one of JavaScript’s primitive values and is treated as falsy for boolean operations. We could compare a value null to a similar primitive value – undefined. Undefined is an unintentional absence of any object value, and this “unintentional” is the thing that differentiates null from the undefined.
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What if you are developing an application that requires a client to upload a file or an image and information about the image via RESTful API and you want the client to send data as JSON? The easy answer would be to perform two posts to REST API.
But is that even possible in a single request?
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Recently I’ve been running into problems trying to save JSON in the MySQL database. Even though MySQL supports JSON type for a while now, there are still plenty of gotchas while you work with it. The situation is pretty critical with special characters. This time we are going to be short and on the topic of invalid JSON characters.
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