Answer:

No. Once a String object has been created you cannot change its data. (Although you can create a new String object that is an altered version of the original.)

Packages

A group of related classes is often put into a collection called a package.

Many packages come standard with Java. For example, the String class is part of the package called java.lang. Several useful classes are part of that package. You can use the classes in this package without doing anything special.

Other standard packages also come with Java. To use a class from one of these packages your program must tell the compiler what package contains the class. One way to do this is to use the package name with the class. Here is a program that explicitly mentions where the String class is found:

public class ImportDemo01
{
  public static void main ( String[] args )
  {
    java.lang.String str;
    int len;

    str = new java.lang.String( "Elementary, my dear Watson!" );

    len = str.length();
    System.out.println("The length is: " + len );
  }
}

This program works the same way as the previous version. The package java.lang does not need to be explicitly mentioned when you need to use String, although it does not hurt to do so.

QUESTION 17:

The class Scanner is not part of the java.lang package. Does a program that creates a Scanner object need to tell the compiler where that class can be found?