4_1

4_1

1. Let's look at what we will learn this in week

   • We will look at arrays of variables
   • and repetition, also called repetition

2. Arrays

   • as seen variables are powerful
   • often we need many of them
     • and sometimes we need a lot of the same type of variable
       • e.g. consider a book record system. Each book could be a variable but there would be thousands of books
   • an array is a special way to organise variables so that we can access and use any variables of the same data type
     • idea: show book shelf in library or chemistry tubes to store in a rack
   • idea: show book shelf in library

3. Rep

   • similarly, we often need to do some functionality many times
     • e.g. drinking tea, I keep taking a sip of tea while there is tea in the cup
   • in programming we can also do that using loops, and we will look at that and how that works especially well with arrays
     • e.g. loop through all the books and check if they have been borrowed and if their due date has been violated

4. last week I asked you to make the smileyface. Did you manage?

   • if (answer == "yes") celebrate(); else learnFromSuppliedCode();
     • should we make a sign?