Java Youth

Tutorial # 6

   The Enhanced for loop

   It is also sometime called as “for each loop” which mainly help to go through all the collection
   elements efficiently.

            Syntax:-

            For(Type identifier: Expression)

            {

                        //statements;

            }

   Where, type represents the data-type or object used & Identifier refers to the name of the   
   variable & Expression is an instance of java.lang.Iterable interface or simply an array.

            E.g=> consider the following statement:

            int numarray[3]={56,48,79}

            for (int k=0;k<=3;k++)

            {

                        If(numarray[k]>50 && numarray[k]<100])

                        {

                                    System.out.println(“the selected value is”+numarray[k]);

                        }

            }                      

                        & the above code can be equivalent to the following code-

            int numarray[3]={56,48,79}

            for (int k:numarray)

            {

                        If(k>50 && k<100)

                        {

                                    System.out.println(“the selected value is”+k);

                        }

            }

   Jumps in loop

            Jump is mainly used to change the continuous flow of execution of the program  
   according to a given predefined condition.

·               Jumping out of the loop

            Can be accomplished by using “break” statement. But remember friends, it can only be
    used with switch statement & looping statements thats too just to exit from the 
    immediate single loop in which the programming is currently executing.

·              Skipping a part of the loop

            Can be mainly accomplished by using “continue” statement, It mainly tells the compiler     to skip the following statements & continue with the next iteration.

  Labelled loop

   In java we can give a label to any block of statements. A label is simply any valid java variable
   name.

            To give a label to a block simply place it before the block with colon at the end.

                        E.g=>

                        loop1:  for(……)

                                    {

                                                …………

                                                …………

                                    }

                                    ………………

  NOTE-

   If we want to jump outside a nested loops or to continue a loop that is outside the current  
  one, then we simply have to use the labeled break & labeled continue statement respectively.
                                    E.g=>

         //Use of continue & break statement
                                     class ContinueBreak
                                     {
                                              public static void main(String args[])
                                              {
                                                         Loop1: for (int i=1;i<100;i++)
                                                                      {
                                                                             System.out.println(" ");
                                                                             if(i>=10) break;
                                                                             for(int j=1;j<100;j++)
                                                                             {
                                                                                 System.out.println("*");
                                                                                 if(j==i)
                                                                                     continue Loop1; 
                                                                             }
                                                                      } 
                                                                      System.out.println("termination by break");
                                              }
                                     }