Constructor chaining in Java - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is constructor chaining in Java?

Constructor chaining is the process where one constructor calls another constructor in the same class or parent class to reuse code and initialize objects efficiently.

beginner

How do you call one constructor from another in the same class?

You use the keyword this() with appropriate parameters inside a constructor to call another constructor in the same class.

beginner

How do you call a parent class constructor from a child class constructor?

You use the keyword <code>super()</code> with parameters inside the child class constructor to call the parent class constructor.

beginner

Why is constructor chaining useful?

It helps avoid code duplication by reusing constructor code, making the code cleaner and easier to maintain.

intermediate

What happens if you don't explicitly call this() or super() in a constructor?

Java automatically inserts a call to the no-argument constructor of the parent class (super()) if no explicit call is made.

Which keyword is used to call another constructor in the same class?

A this()

B super()

C new

D constructor()

The keyword this() calls another constructor in the same class.

What does super() do in a constructor?

A Calls the parent class constructor

B Calls a constructor in the same class

C Creates a new object

D Calls a static method

super() calls the parent class constructor.

What is the main benefit of constructor chaining?

A Faster program execution

B Allows multiple inheritance

C Avoids code duplication

D Enables method overloading

Constructor chaining helps avoid code duplication by reusing constructor code.

If no constructor call is made explicitly, what does Java do?

A Skips constructor execution

B Calls <code>this()</code> automatically

C Throws an error

D Calls the parent class no-argument constructor

Java automatically calls the parent class no-argument constructor if no explicit call is made.

Can constructor chaining happen between different classes?

A Yes, using <code>this()</code>

B Yes, using <code>super()</code>

C No, only within the same class

D No, constructors cannot call each other

Constructor chaining between classes happens using super() to call parent class constructors.

Explain constructor chaining and how it helps in Java programming.

Think about how constructors can call each other to avoid repeating code.

Describe the difference between using this() and super() in constructors.

Consider the relationship between classes and constructors.