Salesforce Plat-Dev-301 Exam Questions

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In Apex, 'bulkification' is the practice of ensuring code can handle multiple records efficiently without hitting governor limits. Snippet A demonstrates the correct bulkified approach for this requirement. It first iterates through the opportunityList to collect all unique AccountId values into a Set. Then, it performs a single SOQL query to retrieve all relevant Accounts and their child Contacts using a subquery (Inner Join). This ensures that the code only consumes one SOQL query regardless of how many opportunities are in the input list.

Snippet B is syntactically incorrect and will fail to compile. In Apex, you cannot use dot-notation (like opportunityList.AccountId) on a List collection to retrieve a set of IDs from its elements. To access the AccountId of records within a list, you must iterate through the list or use a map. Even if corrected to use a proper ID collection, Snippet A is often preferred when you need the relationship context between the Account and its Contacts. Most importantly, Snippet A correctly identifies the need to extract IDs into a separate collection before querying, which is a fundamental requirement for writing scalable Apex. It avoids the 'Query in a loop' anti-pattern and adheres to the platform's execution model.

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Comprehensive and Detailed 1

The fundamental principle of DRY (Don't Repeat Yourself) in Apex development dictates that logic used in multiple places should be centralized. For API integrations, this typically invo2lves creating a Utility or Service Class (Option A).

This class handles the common 'plumbing' of the integration:

Retrieving Named Credentials.

Setting headers (Content-Type, Timeout).

Standardizing error handling and logging.

Serializing and deserializing JSON payloads.

By invoking this central class from various triggers, batch jobs, or controllers, the developer ensures that any change to the API (such as a version update or header change) only needs to be made in one place. Option B leads to 'class sprawl' and duplicate boilerplate code. Option C is incorrect as Static Resources cannot contain executable Apex code. Option D is the definition of poor maintainability.

Comprehensive and Detailed

When dealing with Large Data Volumes (LDV)---specifically in the range of hundreds of thousands to millions of records---the Bulk API (Option C) is the only optimal choice.

The Bulk API is based on REST principles but is optimized for processing large sets of data asynchronously. Instead of processing records one by one or in small synchronous chunks (which would hit time limits and consume many API calls), the Bulk API allows you to upload a CSV file or JSON batch. Salesforce then processes these records in the background using parallel processing.

Options A and B (REST/SOAP) are designed for real-time, synchronous interactions with a limited number of records and would hit rate limits or timeout for millions of records. Option D is for custom logic and is subject to the same synchronous execution limits as standard REST.

This scenario highlights a common conflict in multi-admin environments known as 'the last delivery wins' problem. When multiple administrators work in isolated sandboxes, they are essentially working on different versions of the same metadata. If Admin A adds a field to a Page Layout and deploys it, and then Admin B---who does not have Admin A's changes in their sandbox---deploys their own version of that same Page Layout, Admin B's deployment will overwrite Admin A's changes in Production (Statement B). In the Metadata API (which Change Sets use), Page Layouts are treated as single files; you cannot 'merge' them via a Change Set; you can only replace the destination file entirely.

To resolve this, the team needs a more sophisticated deployment pipeline. Statement D is the correct resolution: the company should implement a 'Staging' or 'Integration' sandbox. In this model, all admins deploy their Change Sets to a single unified sandbox first. This allows them to identify conflicts and 'merge' their changes (manually or via source control) before a final, combined deployment is made to Production. Statement A is technically incorrect because Change Sets cannot 'delete' components; they can only overwrite or add. Statement C is a myth; Page Layouts can be safely deployed, but only if the underlying fields and security settings are also included and coordinated.

In Visualforce, the 'View State' is a hidden form field that maintains the state of the page (and the controller's variables) across postbacks to the server. If the View State becomes too large, it can slow down page loads and eventually hit the Salesforce View State limit (170KB), causing the page to crash.

The transient keyword is used to declare instance variables in Apex controllers that should not be saved in the View State. When a variable is marked as transient, its value is discarded after the request finishes and is not transmitted back to the client. This effectively reduces the size of the View State. It is commonly used for data that is needed only for the duration of the current request (like a large list of records displayed in a read-only table) and can be easily requeried or recalculated if needed.