Question
Answer and Explanation
In JavaScript, the concept of "complaining" about private properties usually refers to the idea of trying to access or modify properties that are intended to be hidden from direct external access. Unlike some languages like Java or C++, JavaScript did not have built-in mechanisms for private class members for a long time. This has led to various workarounds and patterns that developers used to emulate privacy.
Prior to ES2015 (ES6), the most common technique to achieve a semblance of private members was using naming conventions, such as prefixing properties with an underscore (`_`). For example, `_myPrivateProperty`. However, this approach does not offer real privacy; it's simply a convention that communicates to other developers not to access or modify that property from outside the object. There's nothing technically stopping them from doing so.
Another common approach involved using closures and the Module Pattern. By creating a function scope and declaring variables inside, these variables are not directly accessible from the outside, simulating private properties. However, this method can be cumbersome and verbose. With the introduction of ES2015 classes, WeakMaps were sometimes utilized to create private properties, but this also required extra setup.
Finally, with ECMAScript 2022, JavaScript introduced actual private class fields using the `#` prefix. For example, `#myPrivateField`. Trying to access these fields outside of the class throws a syntax error. This is a genuine, built-in mechanism for enforcing privacy. So, in short, "complaining" about private properties usually means encountering an error or limitation while trying to bypass this privacy mechanism. When trying to access a private field defined with `#`, you will get a syntax error, effectively preventing any external access. So, you're not "complaining" in the sense of reporting a bug, but experiencing the enforced privacy feature of JavaScript.