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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 714 · 40 questions
TalentJR

Developer's tip (Write once, use often): function name(parameter) { …; return result; } — call it with name(value). Work out each call separately, then finish the line. Inside a function, if / return can give different results for different inputs.

NameDateTime takenScore ___ / 40
  1. 1.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(10));
  2. 2.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hi, Arjun! (b) Hi, name! (c) greet (d) Arjun
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) Hi, Meera! (b) Hi, name! (c) Meera (d) greet
  5. 5.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 40;
    }
    show(fee(2) + fee(4));
  6. 6.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  7. 7.🧰 What does return do in a function? (a) closes the screen (b) repeats the code (c) sends back a value (d) deletes the app
  8. 8.🧰 How do you run (call) a function called greet? (a) greet[] (b) #greet (c) run greet (d) greet()
  9. 9.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(23));
  10. 10.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 20;
    }
    show(fee(2) + fee(1));
  11. 11.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 3));
  12. 12.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  13. 13.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 3));
  14. 14.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(34));
  15. 15.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(22));
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Well done, name! (c) Well done, Kabir! (d) Kabir
  17. 17.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Hello, name! (b) greet (c) Hello, Riya! (d) Riya
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) Hi, name! (c) greet (d) Hi, Kabir!
  19. 19.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 6));
  20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(3));
  21. 21.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 40;
    }
    show(fee(5) + fee(4));
  22. 22.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, Arjun! (b) Well done, name! (c) greet (d) Arjun
  23. 23.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(25));
  24. 24.🧰 In function tip(bill), what is bill? (a) a screen (b) a loop (c) an event (d) a parameter
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Welcome, name! (c) Welcome, Riya! (d) greet
  26. 26.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 30;
    }
    show(fee(3) + fee(12));
  27. 27.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 30;
    }
    show(fee(3) + fee(7));
  28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 2));
  29. 29.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  30. 30.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 40;
    }
    show(fee(1) + fee(3));
  31. 31.🧰 Why write a function? (a) to hide errors (b) to make code longer (c) to reuse code (d) to slow the app
  32. 32.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Welcome, name! (b) Welcome, Kabir! (c) greet (d) Kabir
  33. 33.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 5));
  34. 34.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(33));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Hello, name! (d) Hello, Aman!
  36. 36.🧰 What is a function? (a) a screen size (b) a type of phone (c) a named block of code (d) a list of colours
  37. 37.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera"));     (a) greet (b) Welcome, name! (c) Welcome, Meera! (d) Meera
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(4));
  39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 6));
  40. 40.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hello, name! (b) Hello, Arjun! (c) greet (d) Arjun

Answer key

  1. 20
  2. 30
  3. Hi, Arjun!
  4. Hi, Meera!
  5. 0
  6. 30
  7. sends back a value
  8. greet()
  9. 46
  10. 0
  11. 195
  12. 50
  13. 300
  14. 102
  15. 44
  16. Well done, Kabir!
  17. Hello, Riya!
  18. Hi, Kabir!
  19. 420
  20. 90
  21. 40
  22. Well done, Arjun!
  23. 75
  24. a parameter
  25. Welcome, Riya!
  26. 30
  27. 30
  28. 150
  29. 20
  30. 0
  31. to reuse code
  32. Welcome, Kabir!
  33. 150
  34. 66
  35. Hello, Aman!
  36. a named block of code
  37. Welcome, Meera!
  38. 80
  39. 480
  40. Hello, Arjun!

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