When a Promise is created, it starts in the "Pending" state. This means that the Promise is neither fulfilled nor rejected. It's essentially in a pending state until the asynchronous operation it represents is completed.

Weak references in WeakMap and WeakSet enable automatic memory management by allowing the garbage collector to reclaim objects that are no longer reachable.

Dynamic Imports in JavaScript allow for efficient code splitting. By loading only the modules that are needed at runtime, it improves the performance of the application, especially in large projects where not all code is required on every page.

Static methods in ES6 classes are defined using the static keyword and are bound to the class itself rather than to instances of the class. These methods are associated with the class constructor and are called on the class, not on instances. Static methods are often used for utility functions that are related to the class but don't depend on specific instance data.

Destructuring in JavaScript allows extracting values from objects or arrays, and when the structure doesn't match, it simply ignores the mismatched values, assigning undefined to the corresponding variables. This behavior is useful for extracting only the needed values and ignoring the rest.

Arrow functions do not have their own this context, making them unsuitable for methods that need access to the object's this value. Constructor functions, which initialize objects and rely on this, should not be implemented using arrow functions.

In ES6 modules, imports and exports must be explicit, meaning they are statically determined at compile-time. This allows for better tooling support and optimizations. CommonJS, on the other hand, allows dynamic imports and exports.

Symbols can be shared globally by using the Symbol.for() method, which creates a shared Symbol registry accessible across different parts of your code. This promotes consistency and reusability.

The call stack in JavaScript tracks the execution of functions. When a function is called, it's added to the stack, and when it returns, it's removed. Blocking occurs when a function takes a long time to execute, causing subsequent code to wait. Understanding this helps optimize code for performance.

In a caching mechanism, using a WeakMap is preferred over a Map. This is because a WeakMap allows the keys to be garbage collected if there are no other references to them, which is beneficial for caching scenarios where you want the cached data to be automatically cleared when the corresponding objects are no longer in use. A Map, on the other hand, would retain the keys even if they are not needed anymore, leading to potential memory leaks in a caching context.

To re-export all named exports from a module in ES6, you use the export * from 'moduleName'; syntax. This allows you to export all the named exports from one module to another without listing them individually.

When importing a named export in ES6, you use the syntax import { exportName } from 'module';. This allows you to bring in a specific exported item from the module.