Listening Questioning Collaboration Communication Risk-Taking Persevering Planning Entry routine 1. Stationery out – you should have your own equipment 2. Exercise books out 3. Planners out 4. Bags underneath table 5. Login to computer account 6. Do Now Task 7. Todays title: For Loops (Counter-Controlled) 8. Draw on the confidence scale where you think you are with the objectives Reflection Listening Questioning Collaboration Communication Risk-Taking Persevering Planning Starter Activity – A Task to Do Now You may not know all of these… but have a go and note down the answers afterwards Reflection Listening Questioning Collaboration Communication Risk-Taking Starter Activity Answers Persevering Planning Reflection Listening Questioning Collaboration Communication Risk-Taking Persevering Planning Reflection Objectives/Outcomes Syllabus Todays title: FOR Loops (Counter-Controlled) By the end of this lesson you will be able to: a) Identify the key parts of a FOR loop b) Describe what a FOR loop is for c) Explain how a FOR loop works d) Use a FOR loop in Visual Basic Plot on the scale to show how confident you feel having looked at the objectives of the lesson. Listening Questioning Collaboration Communication Risk-Taking Persevering Planning Reflection Programming Constructs Three programming constructs that we always program with: 1. Sequence 2. Selection 3. Iteration Each line of code is executed one line after the other – in sequence IF statements SELECT Case statements FOR Loops Conditional Loops (While loops, Do/Until Loops) Listening Questioning Collaboration Communication Risk-Taking Persevering Planning Loops A loop allows us to perform a common programming task multiple times in a more efficient manner (using fewer lines of code). Advantage: reduces programming time. E.g. Outputting hello ten times Without Loop: With Loop: Reflection Listening Questioning Collaboration Communication Risk-Taking Persevering Planning Reflection FOR Loop A FOR loop is a counter-controlled loop; meaning that it iterates (repeats) a fixed number of times. Every FOR loop starts with the word ‘FOR’ This is a variable. We usually call it ‘counter’ but it doesn’t have to be. It does not need to be declared, and only exists within this loop. This tells us the values that counter will start and end at. In this case, it will start at 1 and end at 10. It increases by 1 every time the program reaches the word ‘Next’. The loop end when ‘counter’ reaches 10. And ends with the word ‘Next’. (When the program reads the word next, it jumps back up to the beginning of the FOR loop). The code to be repeated Write code and summarise text How many times does this loop iterate (repeat)? Listening Questioning Collaboration Communication Risk-Taking Persevering Planning Reflection For loop questions How many times do the following loops iterate? (write questions and answers in books) 1. For counter = 1 to 8 8 times (Counter 1,2,3,4,5,6,7,8) 2. For counter = 3 to 7 5 times (Counter 3,4,5,6,7) Self – Assess /7 3. For counter = 0 to 5 6 times (Counter 0,1,2,3,4,5) 4. For counter = 0 to 1 2 times (Counter 0,1) 5. For counter = 1 to 10 Step 2 5 times (Counter 1,3,5,7,9) 6. For counter = 5 to 0 Step -1 6 times (Counter 5,4,3,2,1,0) 7. For counter = 1 to 10 Step 5 2 times (Counter 1,5) Hint: ‘Step’ tells us how much counter will change by every time the program reaches the word ‘Next’. By default it is +1 (and therefore we don’t write Step 1) Listening Questioning Collaboration Communication Risk-Taking Persevering Planning Reflection For loop Tasks 1. Write a program that outputs the phrase ‘Red lolly, Yellow lorry’ 10 times using a loop. 2. Write a program that outputs the value of ‘counter’ 5 times in a loop. 3. Write a program that outputs the words “The value of counter is: ” and the value of counter at that point in the loop (5 times) (E.g. In the third iteration it should output ‘The value of counter is: 3’) 4. Write a program that outputs the words “The value of counter is: ” and the value of counter at that point in the loop (5 times) IN REVERSE ORDER 5,4,3,2,1, Listening Questioning Collaboration Communication Risk-Taking For loop task ANSWERS Task 1: Task 3: Task 2: Task 4: Persevering Planning Reflection Listening Questioning Collaboration Communication Risk-Taking Persevering Planning Reflection Programming Task Write a program that asks the user to enter a number between 1 and 3. Keep adding one to their value ten times. Each time you add one, it should check if the value is: - equal to 3 (If it is, then output the words ‘your value is now 3’) - equal to 6 (if it is, then output the words ‘your value is now 6’) - equal to 9 (if it is, then output the words ‘your value is now 9’) - equal to 10 (if it is, then output the words ‘Final value is 10’) Hint: To add 1 to a variable: Score = Score + 1 Listening Questioning Collaboration Communication Risk-Taking Persevering Programming Task Answers OR Planning Reflection Listening Questioning Collaboration Communication Risk-Taking Persevering Planning Reflection Syllabus Plenary - Self Evaluation By the end of this lesson you will be able to: a) Identify the key parts of a FOR loop b) Describe what a FOR loop is for c) Explain how a FOR loop works d) Use a FOR loop in Visual Basic Plot on the scale to show how confident you feel having looked at the objectives of the lesson.
