SALESFORCE-PD1 Developer Fundamentals Practice Question
A developer needs to store a collection of unique customer email addresses in Apex and check for existence efficiently. Which collection type should the developer use?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Set
A Set is a collection of unique elements and provides efficient lookup using methods like contains(), making it ideal for checking existence.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Queueable
Why it's wrong here
Queueable is an interface used for asynchronous processing, not a collection type.
- ✗
List
Why it's wrong here
Lists allow duplicate values and require linear scans for existence checks.
- ✗
Map
Why it's wrong here
Maps store key-value pairs, which is overkill for a simple collection of unique values.
- ✓
Set
Why this is correct
Sets contain unique elements and offer fast lookups.
About these practice questions
This SALESFORCE-PD1 question is part of Courseiva's 488-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official Salesforce exam blueprint
This SALESFORCE-PD1 practice question is part of Courseiva's free Salesforce certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SALESFORCE-PD1 exam.