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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 150 · 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 points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(5));
  2. 2.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya"));     (a) Hi, name! (b) Riya (c) greet (d) Hi, Riya!
  3. 3.🧰 What does return do in a function? (a) repeats the code (b) sends back a value (c) closes the screen (d) deletes the app
  4. 4.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
  5. 5.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 2));
  6. 6.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 6));
  7. 7.🧰 In function tip(bill), what is bill? (a) a loop (b) a screen (c) an event (d) a parameter
  8. 8.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(39));
  9. 9.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Welcome, Aman! (b) Aman (c) Welcome, name! (d) greet
  10. 10.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 3));
  11. 11.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(7));
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hi, name! (b) Hi, Zoya! (c) Zoya (d) greet
  13. 13.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(9));
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Hi, name! (b) Hi, Aman! (c) Aman (d) greet
  15. 15.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Well done, name! (c) Kabir (d) Well done, Kabir!
  16. 16.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Welcome, name! (c) Arjun (d) Welcome, Arjun!
  17. 17.🧰 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(2) + fee(8));
  18. 18.🧰 How do you run (call) a function called greet? (a) run greet (b) greet() (c) greet[] (d) #greet
  19. 19.🧰 Why write a function? (a) to reuse code (b) to make code longer (c) to hide errors (d) to slow the app
  20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(5));
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Well done, Aman! (c) Well done, name! (d) Aman
  22. 22.🧰 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(6));
  23. 23.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(3));
  24. 24.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(26));
  25. 25.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 2));
  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 20;
    }
    show(fee(5) + fee(5));
  27. 27.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 4));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Hello, Zoya! (c) Zoya (d) Hello, name!
  30. 30.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 3));
  31. 31.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 2));
  32. 32.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
  33. 33.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, Riya! (b) greet (c) Riya (d) Well done, name!
  34. 34.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(5));
  35. 35.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(17));
  36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 6));
  37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(3));
  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(8) + fee(9));
  39. 39.🧰 What is a function? (a) a list of colours (b) a screen size (c) a type of phone (d) a named block of code
  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 30;
    }
    show(fee(9) + fee(4));

Answer key

  1. 90
  2. Hi, Riya!
  3. sends back a value
  4. 40
  5. 140
  6. 450
  7. a parameter
  8. 117
  9. Welcome, Aman!
  10. 120
  11. 21
  12. Hi, Zoya!
  13. 18
  14. Hi, Aman!
  15. Well done, Kabir!
  16. Welcome, Arjun!
  17. 60
  18. greet()
  19. to reuse code
  20. 70
  21. Well done, Aman!
  22. 60
  23. 60
  24. 78
  25. 50
  26. 40
  27. 20
  28. 120
  29. Hello, Zoya!
  30. 45
  31. 100
  32. 70
  33. Well done, Riya!
  34. 10
  35. 51
  36. 270
  37. 50
  38. 40
  39. a named block of code
  40. 30

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