Page 104 - Computer Genius Class 06
P. 104

Apply Loops and Conditionals with Sequencing

                  Let us learn how to use loops and conditional with the help of sequencing.

                  Selection

                  Selection can be described as making a choice based on a criteria. Think of it as IF this THEN that.
                   election is an important part o  coding.  t helps us to choose different paths and react to situations.
                  Example: ‘Is it raining today?”

                     If the answer to the question is true, then the algorithm follows one path.
                     If the answer is false, the algorithm follows a different path.

                  Iteration

                  To run a  loc  o  code specific num er o  times  iteration is used.  teration can  e defined as doing
                  or repeating the same tas  again and again until the specified condition is met.  teration is repeating
                  situations.
                  Example:  n a car race  a car must go around a trac  fi e times. The car  ill  eep going around the trac
                  repeatedly until it completes fi e laps.  nce it is done  it  ill e it the trac .

                  Now let’s combine all the three building blocks of an algorithm:  sequencing, selection, and iteration.
                  Let’s look at our cup of tea task with sequence, selection and iteration. We have the same number
                  o  steps  ut our process has  ecome more precise  ho  long to stir  or   e cient   e don t fill the
                  kettle if it has water in it already) and we have choice (milk or no milk).
                   Step 1   IF the kettle has no water THEN fill the kettle with water

                   Step 2   Turn the kettle on
                   Step 3   Put tea bag in the cup
                   Step 4   Pour hot water into the cup

                   Step 5   Remove tea bag
                   Step 6   IF you take milk THEN add milk
                   Step 7    If you take sugar THEN add sugar. Stir until the milk has been mixed into the tea

                  In real life, complex algorithms can have hundreds of steps in a sequence and there are certain activities
                  in the sequence which are repeated. We can reduce the number of steps of the sequence by using a loop
                  along with certain conditions to check when the loop should stop.

                  What is a Bug?

                     ug is an une pected pro lem in your program.  ou  ollo  a defined se uence to  rite a program
                   rom  hich you e pect to return a specific output.  ny change in the e pected and actual output o
                  the program is said to be the result of a bug.

                  So, we can say that  bug is a general term which is used to describe any unexpected problem with
                  hardware or software.

                  Example:  Suppose you are going out for a family picnic. You are ready to go, but you notice that
                  the tyre of the car is puncture, due to which your picnic will get delayed for few hours or you need
                  to postpone it  or some other day.  s first you need to repair the tyre.  o  this puncture in the tyre
                  of the car can be termed as a ‘bug’ in programming.


                      102    Computer Genius-VI
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