Page 306 - Computer Science V2.0 Class 11
P. 306

Note that the range()  function returns an immutable sequence of values and that the control variable i  takes
              values from this sequence. So, changing the value of the control variable in the body of the for statement does not
              change the flow of execution of the for statement.
              11.3.5 More Examples of for Statement

              In Table 11.2, we give some more examples of the use of the for statement:
                                                   Table 11.2: Statements using for loop

                              Statements                           Output                      Description
               for ch in 'ABCD':                          A                        The control  variable ch takes each
                   print(ch)                              B                        value  in  the  sequence  of  characters:
                                                          C                        'A', 'B', 'C', 'D'
                                                          D
               numbers = [9, 0, -4, 23, 17, 56]           0                        The control variable n takes  values
               for n in numbers:                          -4                       in the list numbers, one by one. For
                                                                                   each  value of the  control variable,
                  if n%2 == 0:                            56
                                                                                   n, from the list  numbers, print
                     print(n)                             Job Done
                                                                                   statement is executed if n%2 == 0.
               print('Job Done')
                                                                                   The statement print('Job Done')
                                                                                   is  not  part of  the body  of  the loop,
                                                                                   so  it  is  executed  after  the  loop
                                                                                   terminates.
               for x in range(30, 50, 5):                 30                       The control variable, x, takes values in
                  print(x)                                35                       the range of 30 to 50 (excluding 50) in
                                                                                   steps of 5.
                                                          40
                                                          45
               for p in range(4):                         0 1 2 3                  The control  variable p takes  values
                  print(p,  end=' ')                                               in the sequence 0, 1, 2, 3. The default
                                                                                   start value is 0.
               for p in range(100, 90, -2):               100 98 96 94 92 BYE As the body of the for loop is executed,
                  print(p, end=' ')                                                the numbers in the range of 100 to 91
               else:                                                               (in steps of -2) are printed. The else
                                                                                   part of the for loop is executed after
                  print("BYE")
                                                                                   all  iterations  of  the  loop  have  been
                                                                                   executed.

               for c in 'ROSE':                           Good Code                For each value of the control variable
                   if c == 'O':                           O                        c in  the  string  'ROSE', the if-else
                                                                                   statement is executed.
                       print(c)                           Good Code
                   else:                                  Good Code
                       print('Good Code')
               for c in 'ROSE':                           O                        For each value of the control variable c
                   if c == 'O':                           Good Code                in the string 'ROSE' the if statement
                                                                                   is  executed.  The  else clause  is
                       print(c)
                                                                                   part of  the  for statement, and  it  is
               else:
                                                                                   executed after all iterations of the for
                   print('Good Code')
                                                                                   statement have been completed.




               292   Touchpad Computer Science (Ver. 2.0)-XI
   301   302   303   304   305   306   307   308   309   310   311