What callback function do you use to lazy load a script in SFCC?

The correct approach for lazy loading a script in Salesforce Commerce Cloud (SFCC) is to use the loadScript callback function. This function is part of the SFCC front end's JavaScript framework and facilitates the dynamic loading of JavaScript files only when they are needed, rather than loading all scripts upfront. This method improves page load times and overall site performance by deferring loading until the browser requires the script, which is particularly useful for larger JavaScript files or libraries.

loadScript ensures that the script is loaded asynchronously without blocking the rendering of the page. Once loaded, any dependent code can be executed, enabling modular development. This enhances the user experience, especially in complex applications where not all scripts are crucial on initial load.

Other options like require, importScript, and asyncLoad are not specifically designed for lazy loading in the SFCC context. While require is often associated with module loading in JavaScript, it's not tailored for managing script dependencies in the SFCC platform. Similarly, importScript is used for importing scripts but lacks the nuanced control and lazy loading mechanism provided by loadScript. Finally, asyncLoad isn’t a standard callback used in the SFCC ecosystem.