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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 767 · 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(90, 6));
  2. 2.🧰 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(11) + fee(3));
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) greet (b) Aman (c) Welcome, Aman! (d) Welcome, name!
  4. 4.🧰 What does return do in a function? (a) closes the screen (b) repeats the code (c) sends back a value (d) deletes the app
  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 60;
    }
    show(fee(3) + fee(5));
  6. 6.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
  7. 7.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Well done, Meera! (c) Well done, name! (d) greet
  8. 8.🧰 What is a function? (a) a type of phone (b) a named block of code (c) a screen size (d) a list of colours
  9. 9.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Hi, Aman! (b) Aman (c) Hi, name! (d) greet
  10. 10.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(7));
  11. 11.🧰 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(7) + fee(4));
  12. 12.🧰 Why write a function? (a) to reuse code (b) to make code longer (c) to hide errors (d) to slow the app
  13. 13.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(19));
  14. 14.🧰 How do you run (call) a function called greet? (a) greet[] (b) greet() (c) #greet (d) run greet
  15. 15.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(20));
  16. 16.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(34));
  17. 17.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(4));
  18. 18.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(23));
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) greet (b) Well done, Arjun! (c) Arjun (d) Well done, name!
  20. 20.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(20));
  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 30;
    }
    show(fee(3) + fee(5));
  22. 22.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 6));
  23. 23.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 3));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
  25. 25.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hi, Zoya! (b) Zoya (c) Hi, name! (d) greet
  26. 26.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Hello, name! (b) Hello, Meera! (c) greet (d) Meera
  27. 27.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 2));
  28. 28.🧰 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(10));
  29. 29.🧰 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(7));
  30. 30.🧰 In function tip(bill), what is bill? (a) an event (b) a screen (c) a parameter (d) a loop
  31. 31.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(27));
  32. 32.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(4));
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(4));
  34. 34.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
  35. 35.🧰 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(8) + fee(6));
  36. 36.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(11));
  37. 37.🧰 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(1));
  38. 38.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 4));
  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 30;
    }
    show(fee(3) + fee(11));
  40. 40.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));

Answer key

  1. 540
  2. 20
  3. Welcome, Aman!
  4. sends back a value
  5. 60
  6. 40
  7. Well done, Meera!
  8. a named block of code
  9. Hi, Aman!
  10. 21
  11. 50
  12. to reuse code
  13. 57
  14. greet()
  15. 60
  16. 102
  17. 60
  18. 46
  19. Well done, Arjun!
  20. 40
  21. 30
  22. 180
  23. 210
  24. 30
  25. Hi, Zoya!
  26. Hello, Meera!
  27. 50
  28. 20
  29. 50
  30. a parameter
  31. 81
  32. 12
  33. 100
  34. 20
  35. 60
  36. 33
  37. 50
  38. 180
  39. 30
  40. 70

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