Slide 12.18: Generics (cont.): Generic functions Slide 12.20: Generics (cont.): Typecasting Home

Generics (Cont.)

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

• Type safety (cont.): How can generics help to solve this problem? At the time of defining ArrayList, we can specify that this list can take only String objects.
  
  

  WithGenerics.java (generics being used)

  view source print? 01 // Using generics to convert run-time exceptions into compile-time exceptions 02 import java.util.*; 03 class WithGenerics { 04   public static void main( String[ ] args ) { 05     // Creating an ArrayList with String specified 06     ArrayList<String> al = new ArrayList<String>( ); 07     al.add( args[0] ); 08     al.add( args[1] ); 09     // Now compiler doesn't allow the following command. 10     al.add( Integer.parseInt( args[2] ) ); 11   12     String s1 = (String) al.get( 0 ); 13     String s2 = (String) al.get( 1 ); 14     String s3 = (String) al.get( 2 ); 15   } 16 }

  shell> javac WithGenerics.java     |

Slide 12.18: Generics (cont.): Generic functions Slide 12.20: Generics (cont.): Typecasting Home

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