In the JavaScript universe, there are several ways of checking the existence of a property within an object. A common one is the use of the hasOwnPropterty method. The following image shows an example of its use. As we can see, the normal variant also works for null properties.
The syntax in the example above is very simple. Define an object and call the method with the property to be checked. But have you ever asked why, for example, Webpack calls the hasOwnProperty.call variant when bundling. The reason for this is very simple: the common hasOwnPropterty Method is not zero safe! Here is the proof:
In JavaScript, you can also use an object without prototypical inheritance. In this case, an error is thrown in the console. Which is very unpleasant! By using hasOwnProperty.call the problem would disappear into thin air. Let's take a look at the whole thing in another example.
We no longer see any error. Yes, it's an absolutely marginal case. But why not take advantage of the additional security from the outset?
The Webfrontend FG wishes you a wonderful weekend, may the code be with you.
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