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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 134 · 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 total(price, qty) {
      return price * qty;
    }
    show(total(30, 6));
  2. 2.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(3));
  3. 3.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 4));
  4. 4.🧰 Why write a function? (a) to slow the app (b) to hide errors (c) to reuse code (d) to make code longer
  5. 5.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));
  6. 6.🧰 What is a function? (a) a list of colours (b) a named block of code (c) a screen size (d) a type of phone
  7. 7.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 6));
  8. 8.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
  9. 9.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hi, Zoya! (b) Zoya (c) greet (d) Hi, name!
  10. 10.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(4));
  11. 11.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, name! (b) Kabir (c) Hello, Kabir! (d) greet
  12. 12.🧰 How do you run (call) a function called greet? (a) run greet (b) greet[] (c) greet() (d) #greet
  13. 13.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(4));
  14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 3));
  15. 15.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, Aman! (b) greet (c) Hello, name! (d) Aman
  16. 16.🧰 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(7) + fee(10));
  17. 17.🧰 What does return do in a function? (a) closes the screen (b) repeats the code (c) deletes the app (d) sends back a value
  18. 18.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Hello, name! (c) Hello, Meera! (d) greet
  19. 19.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(1));
  20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 5));
  21. 21.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(8));
  22. 22.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 3));
  23. 23.🧰 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(7) + fee(3));
  24. 24.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Welcome, name! (b) greet (c) Welcome, Aman! (d) Aman
  25. 25.🧰 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(4) + fee(3));
  26. 26.🧰 In function tip(bill), what is bill? (a) an event (b) a loop (c) a screen (d) a parameter
  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 20;
    }
    show(fee(10) + fee(4));
  28. 28.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 6));
  30. 30.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 2));
  31. 31.🧰 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(6) + fee(9));
  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 50;
    }
    show(fee(10) + fee(8));
  33. 33.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, Riya! (b) Well done, name! (c) Riya (d) greet
  34. 34.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(34));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Well done, Kabir! (c) Well done, name! (d) Kabir
  36. 36.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(12));
  37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(4));
  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 50;
    }
    show(fee(1) + fee(5));
  39. 39.🧰 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(10));
  40. 40.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(33));

Answer key

  1. 180
  2. 70
  3. 260
  4. to reuse code
  5. 70
  6. a named block of code
  7. 90
  8. 40
  9. Hi, Zoya!
  10. 90
  11. Hello, Kabir!
  12. greet()
  13. 60
  14. 285
  15. Hello, Aman!
  16. 60
  17. sends back a value
  18. Hello, Meera!
  19. 50
  20. 75
  21. 24
  22. 240
  23. 60
  24. Welcome, Aman!
  25. 0
  26. a parameter
  27. 20
  28. 50
  29. 600
  30. 60
  31. 60
  32. 100
  33. Well done, Riya!
  34. 68
  35. Well done, Kabir!
  36. 24
  37. 100
  38. 50
  39. 80
  40. 66

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