Primitive data types are built in data types which are a part of the wrapper classes. These wrapper classes are encapsulated in the java.lang package. Non primitive datatypes like Scanner class are a part of the utility package for which an object needs to be created.

(a) To which package the Character and Boolean classes belong?

(b) Write the statement to access the Scanner class in the program.

A student is trying to convert the string present in x to a numerical value, so that he can find the square root of the converted value. However the code has an error. Name the error (syntax / logical / runtime). Correct the code so that it compiles and runs correctly.

String x= "25";
int y=Double.parseDouble(x); 
double r=Math.sqrt(y); 
System.out.println(r);

Differentiate between boxing and unboxing.

The method to convert a String to double is:

1. String.toDouble()
2. Double.Parsedouble()
3. Double.parseDouble(String)
4. Double.parseDouble()