What is a constructor in Java?
Why Interviewers Ask This
Foundational questions like this help interviewers calibrate the rest of the interview. A confident, accurate answer signals that you have solid Java basics — a prerequisite for any developer role.
Answer
A constructor is a special method that is automatically called when an object is created with new. It has the same name as the class and no return type (not even void). Constructors initialize the object's state: public Car(String color, int speed) { this.color = color; this.speed = speed; }. If you do not define any constructor, Java provides a default no-argument constructor that initializes fields to their default values. Constructors can be overloaded (multiple constructors with different parameters). One constructor can call another using this() (constructor chaining).
Common Mistake
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