this Keyword

this Keyword

1. What Is this? (beginner)

this = "myself!" — address of current object. Fixes shadowing (param same name as field!) + enables chaining + passes self.

class Student {
    String name;
    Student(String name) {
        // name = name; // USELESS (param = param, field untouched!)
        this.name = name; // field = param (correct!)
    }
    void show() { System.out.println(this.name); } // this optional here
}

4. Traps

• this in static = ERROR (no object!).
• this(...) must be FIRST line of constructor.
• this == obj compares self-address (rare).

5. Exam Points

• Shadowing fix program — 5 marks, very frequent.
• this() chaining + static ban — 3-5 marks, frequent.