Describe Use Cases for JavaScript in a Visualforce Page. PLATFORM-DEVELOPER-II Practice Questions (Page 3)

Questions 11–15

1. 11application · medium

   A developer is adding jQuery to a Visualforce page to enhance client-side interactions. The page already uses Salesforce's built-in JavaScript (like SObject and AJAX toolkit). What is the best practice to avoid conflicts between jQuery and other JavaScript libraries on the page?

   • ALoad jQuery before all other scripts and use the global $ symbol exclusively for jQuery.
   • BRename all jQuery functions to custom names using jQuery's rename method.
   • CUse jQuery's noConflict mode and wrap all jQuery code in an IIFE that passes the local $ variable.
   • DAvoid using jQuery and instead write all JavaScript in vanilla JavaScript to eliminate any library conflicts.
   Reveal Solution Discussion Select an answer first
2. 12application · medium

   A developer is writing JavaScript for a Visualforce page that will be used by multiple communities. They want to ensure that the JavaScript does not interfere with other scripts running on the same page. Which practice is most important?

   • AUse the Salesforce AJAX toolkit's SObject model for all data operations to avoid conflicts.
   • BWrap all JavaScript in an IIFE (Immediately Invoked Function Expression) and avoid creating global variables.
   • CLoad the JavaScript at the end of the page body to ensure it runs after other scripts.
   • DUse descriptive variable names that are unlikely to conflict with other scripts.
   Reveal Solution Discussion Select an answer first
4. 13expert · hard

   A developer is building a complex Visualforce page with many interactive components. They are concerned about performance and maintainability. They have decided to use JavaScript to manipulate the DOM. Which practice is most important to ensure the page remains performant and maintainable?

   • AUse jQuery's .html() method to replace large sections of the page to simplify code.
   • BUse inline event handlers for simplicity, as they are easier to write and debug.
   • CAvoid using any JavaScript libraries and write all code in vanilla JavaScript to reduce dependencies.
   • DMinimize DOM manipulations by batching updates and using document fragments when adding multiple elements.
   Reveal Solution Discussion Select an answer first
5. 14foundation · easy

   What is the purpose of using AJAX in a Visualforce page to interact with Salesforce data?

   • ATo replace the need for Apex controllers entirely
   • BTo render Visualforce components on the server
   • CTo create static resources for the page
   • DTo make asynchronous requests to the server to retrieve or update data without a full page reload
   Reveal Solution Discussion Select an answer first
6. 15foundation · easy

   What is the recommended way to reference a JavaScript library stored as a static resource in Visualforce?

   • AUse the $Resource global variable in a <script> tag's src attribute
   • BUse the <apex:resource> tag to embed the library
   • CUse the <script> tag with a relative path to the resource
   • DUse the <apex:script> tag with the resource name
   Reveal Solution Discussion Select an answer first