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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 572 · 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.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 50;
    }
    show(fee(8) + fee(8));
  2. 2.🧰 What does return do in a function? (a) repeats the code (b) deletes the app (c) sends back a value (d) closes the screen
  3. 3.🧰 How do you run (call) a function called greet? (a) #greet (b) greet() (c) run greet (d) greet[]
  4. 4.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Hello, Aman! (c) greet (d) Hello, name!
  5. 5.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Welcome, Kabir! (b) Kabir (c) Welcome, name! (d) greet
  6. 6.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(16));
  7. 7.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(17));
  8. 8.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(4));
  9. 9.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 2));
  10. 10.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hi, name! (b) Hi, Zoya! (c) greet (d) Zoya
  11. 11.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Well done, name! (b) Kabir (c) Well done, Kabir! (d) greet
  12. 12.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  13. 13.🧰 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(12) + fee(6));
  14. 14.🧰 Why write a function? (a) to make code longer (b) to hide errors (c) to slow the app (d) to reuse code
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Well done, name! (b) greet (c) Well done, Arjun! (d) Arjun
  17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 4));
  18. 18.🧰 What is a function? (a) a type of phone (b) a named block of code (c) a screen size (d) a list of colours
  19. 19.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(13));
  20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  21. 21.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(2));
  22. 22.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(9));
  23. 23.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) greet (c) Welcome, name! (d) Welcome, Riya!
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Well done, name! (b) Well done, Meera! (c) greet (d) Meera
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Well done, Aman! (c) Aman (d) Well done, name!
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 6));
  27. 27.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Welcome, Zoya! (c) Welcome, name! (d) Zoya
  28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 6));
  29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 5));
  30. 30.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(5));
  31. 31.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(40));
  32. 32.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 60;
    }
    show(fee(3) + fee(3));
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
  34. 34.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 60;
    }
    show(fee(4) + fee(8));
  35. 35.🧰 In function tip(bill), what is bill? (a) an event (b) a parameter (c) a loop (d) a screen
  36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 5));
  37. 37.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(22));
  38. 38.🧰 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(3) + fee(2));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Hello, Zoya! (c) Hello, name! (d) Zoya
  40. 40.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 50;
    }
    show(fee(3) + fee(2));

Answer key

  1. 100
  2. sends back a value
  3. greet()
  4. Hello, Aman!
  5. Welcome, Kabir!
  6. 32
  7. 51
  8. 8
  9. 30
  10. Hi, Zoya!
  11. Well done, Kabir!
  12. 20
  13. 40
  14. to reuse code
  15. 30
  16. Well done, Arjun!
  17. 280
  18. a named block of code
  19. 26
  20. 60
  21. 60
  22. 27
  23. Welcome, Riya!
  24. Well done, Meera!
  25. Well done, Aman!
  26. 60
  27. Welcome, Zoya!
  28. 390
  29. 475
  30. 70
  31. 120
  32. 0
  33. 40
  34. 60
  35. a parameter
  36. 375
  37. 66
  38. 0
  39. Hello, Zoya!
  40. 0

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