Java Interview Practice Problem (Beginner): Distinct Email IDs

Solution for Java Interview Practice Problem

Problem

• The Frontend application allows the marketing team to upload email addresses. But there maybe cases where this upload feature contains duplicate email addresses which will cause a unique constraint violation in the database.
• Write a Java program that reads and outputs only unique user emails so that I can persist into the database without any constraint violation.

Example

input email list

• Our input list contains an email address. As we can see there is a duplicate for “pqr@pqr.com”, and “abc@abc.com”.

[zt1jegib68@abc.com, 95fv6s8e1m@gmail.com, pijuupwmwa@gmail.com, pqr@pqr.com, pqr@pqr.com, abc@abc.com, abc@abc.com]

Output

• Our output only has one occurrence of “pqr@pqr.com”, and “abc@abc.com”.

[zt1jegib68@abc.com, 95fv6s8e1m@gmail.com, pijuupwmwa@gmail.com, pqr@pqr.com, abc@abc.com]

Before jumping to the solution consider giving an attempt.

Solution

Sample Input Data

public static void main(String[] args) {…