Slide 12.20: Generics (cont.): Typecasting

Slide 12.19: Generics (cont.): Advantages
Slide 12.a: A word counter
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Generics (Cont.)

Advantages of Generics (Cont.)
Programs that uses generics have many benefits over non-generic code (cont.):

Individual type casting not needed: If we do not use generics, then in the previous example, every time we retrieve data from ArrayList, we have to typecast it. Typecasting at every retrieval operation is a big headache. If we already know that our list only holds String data, then we need not to typecast it every time.

NoTypecast.java (generics saving typecasting)

// No need to typecast individual members of ArrayList.
import java.util.*; 
class NoTypecast { 
  public static void main( String[ ] args ) { 
    // Creating an ArrayList with String specified 
    ArrayList<String> al = new ArrayList<String>( );
    al.add( args[0] );
    al.add( args[1] ); 
    // Typecasting is not needed.
    String s1 = al.get( 0 );
    String s2 = al.get( 1 ); 
    System.out.println( s1 + ": " + s2 + " year" );
  } 
}

shell> java NoTypecast (string) (string)

Output:

Implementing generic algorithms: By using generics, we can implement algorithms that work on different types of objects and at the same they are type safe too.

Slide 12.19: Generics (cont.): Advantages
Slide 12.a: A word counter
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or condemn yourself to be miserable all your days.
Other people will try to make you miserable;
don’t help them by doing the job yourself.”
― Laurell K. Hamilton