isModuleLoaded

isModuleLoaded is a function commonly found in JavaScript module loading systems, particularly those used in older or custom environments. Its primary purpose is to check if a specific module has already been loaded and initialized. This prevents redundant loading and execution of module code, ensuring that a module's initialization logic runs only once.

When a request is made to load a module, the isModuleLoaded function is typically invoked first. It consults an internal registry or cache that keeps track of all modules that have been successfully loaded. If the requested module's identifier is present in this registry, it means the module is already loaded, and the function returns true.

Conversely, if the module's identifier is not found in the registry, isModuleLoaded returns false, signaling that the module needs to be loaded. This check is crucial for maintaining module integrity and preventing potential conflicts that could arise from multiple instances of the same module. The implementation details of isModuleLoaded can vary significantly depending on the specific module loader being used, such as AMD (Asynchronous Module Definition) or CommonJS, or even custom-built systems. However, the core functionality of checking for prior loading remains consistent.