Constructor Chain with Default Values

In this problem: You will create a UserProfile class with three constructors chained together, progressively setting default values.

Learning Objective: Understand the pattern of chaining multiple constructors with this() to progressively set default values

Overview

In a constructor chain, constructors with fewer arguments add default values and delegate to the constructor with the most arguments. Actual initialization happens only in the final constructor, completely eliminating code duplication.

Specifications

• UserProfile class: name (String), age (int), role (String) fields
• UserProfile(String name): delegates with this(name, 0, "guest")
• UserProfile(String name, int age): delegates with this(name, age, "member")
• UserProfile(String name, int age, String role): initializes all fields
• Override toString() to return profile information

Output Format

UserProfile[name=Alice, age=0, role=guest]
UserProfile[name=Bob, age=25, role=member]
UserProfile[name=Charlie, age=30, role=admin]