What is different among String, StringBuffer, StringBuilder?

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: Constructor is not a special method Constructor is block of code that is executed automatically whenever object of the class is created

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: 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

Correct Answer: Path contains path of exe files(commands) Classpath contains path of packages packages can be stored in folder or jar files

Correct Answer: By using super call we can call super class constructors from sub class constructors and we can initialize super class private data