this can be pointing to current object.
super can be used for accesing super class metods &varibles.
'this &super' are use full for constructers also .
thes two statements defining first satatement of
constructer.'this' is used for accesing current class
constuter.where as super is accessing super class
constructer.
this() call one of user define constructor inside another user constructor of the same class such as this(a), this(a,b) & so on.
super() call one of base class constructor inside the derive class constructor such as super(a), super(a,b) & so on.
this & super is a keyword.
"this" is used to invoke a constructor of a same class,
its pointing the same class object.
"super" is used to invoke a superclass constructor and
accessing the superclass constructor.
1: 'this' keyword is only use to call to parametic
constructors within the same class.
2: 'super' keyword is use to call to parametric
constructors of base class.
String is an immutable object.
Then how can the following code be justified.
String s1 = ?ABC?;
String s1 = s1+?XYZ?;
s.o.p(s1);
The output is ABCXYZ, which is the value of s1 ?
Given:
10. interface A { void x(); }
11. class B implements A { public void x() { } public
voidy() { } }
12. class C extends B { public void x() {} }
And:
20. java.util.List list = new java.util.ArrayList();
21. list.add(new B());
22. list.add(new C());
23. for (A a:list) {
24. a.x();
25. a.y();;
26. }
What is the result?
1 Compilation fails because of an error in
line 25.
2 The code runs with no output.
3 An exception is thrown at runtime.
4 Compilation fails because of an error in
line 20.
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