Understanding the problem without this keyword, this keyword to refer current class instance variable.

Java Programming Language Class, Object and Methods in java (Article) Class, Object and Methods in java (Program)

1076

---

Program:

//Understanding the problem without this keyword
class StudentClass {

    int rollno;
    String name;
    float age;

    StudentClass(int rollno, String name, float age) {
        rollno = rollno;
        name = name;
        age = age;
    }

    void display() {
        System.out.println(rollno + " " + name + " " + age);
    }
}

class MainStudentClass {

    public static void main(String args[]) {
        StudentClass s1 = new StudentClass(1, "Rahim", 21.0f);
        StudentClass s2 = new StudentClass(2, "Ram", 21.5f);
        s1.display();
        s2.display();
    }
}
/* The this keyword can be used to refer current class instance
variable. If there is ambiguity between the instance variables
and parameters, this keyword resolves the problem of ambiguity. */

Output:

0 null 0.0
0 null 0.0
Press any key to continue . . .

---

---