What is Constructor?

Correct Answer: Method contains name, parameters, return type and executable body But block does not contains name, parameters, return typeIt contains only executable body Methods are executed by method call statements Blocks are executed automatically with class loading and with object creation

Correct Answer: By using method The method used to get the data is called getter method

Correct Answer: By using method The method used to set the data is called setter method

Correct Answer: If we are not using packages and if we are not using inheritance then there is no difference among public, protected and package access data

Correct Answer: Whenever there is local- variable/parameter inside the method with same name as data member Ex: Class Sample { int a; void show() { int a=5; systemoutprintln(a); // 5 systemoutprintln(thisa);//23 } } class MainApp { Public static void main(String[] args) { Sample s = new Sample(); sa = 23; sshow(); } }

Correct Answer: new ClassName( arg1, arg2, argN); Ex: Class sample { Sample(int a) { Systemoutprintln("arg con a =" +a); } } class Demo { Public static void main( String[] args) { Sample s1= new Sample(23); Sample s2= new Sample(45); } }

Correct Answer: String class objects are immutable objects and they represents strings( sequence of characters) StringBuffer class objects are mutable objects representing strings and they are Thread safe StringBuild class objects are also mutable objects representing strings and they are not Thread safe

Correct Answer: Wrapping is also called as packing or boxing Storing the data inside the object as private data which can accessed outside the class only by using methods

Correct Answer: Unwrapping is also called as unpacking or unboxing Getting the private data stored in the object by using methods is called unpacking or unwrapping

Correct Answer: JAR files are java's version of ZIP files In fact, JAR uses the ZIP file format uses: - to compress a number of class files into one file - to make a java executable JAR file