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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 772 · 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 40;
    }
    show(fee(4) + fee(4));
  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 number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
  4. 4.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(35));
  5. 5.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 6));
  6. 6.🧰 In function tip(bill), what is bill? (a) a screen (b) a loop (c) a parameter (d) an event
  7. 7.🧰 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(4) + fee(4));
  8. 8.🧰 What is a function? (a) a list of colours (b) a named block of code (c) a type of phone (d) a screen size
  9. 9.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(7));
  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 50;
    }
    show(fee(3) + fee(5));
  11. 11.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(3));
  12. 12.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(28));
  13. 13.🧰 What does return do in a function? (a) closes the screen (b) sends back a value (c) repeats the code (d) deletes the app
  14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 4));
  15. 15.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) Zoya (b) Well done, name! (c) greet (d) Well done, Zoya!
  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 40;
    }
    show(fee(2) + fee(9));
  17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 4));
  18. 18.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(5));
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Riya (b) Hello, name! (c) Hello, Riya! (d) greet
  20. 20.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya"));     (a) Well done, name! (b) Riya (c) greet (d) Well done, Riya!
  21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 4));
  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 40;
    }
    show(fee(3) + fee(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 50;
    }
    show(fee(5) + fee(7));
  24. 24.🧰 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(5));
  25. 25.🧰 How do you run (call) a function called greet? (a) greet() (b) #greet (c) run greet (d) greet[]
  26. 26.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) Welcome, name! (b) Welcome, Riya! (c) greet (d) Riya
  27. 27.🧰 Why write a function? (a) to slow the app (b) to hide errors (c) to reuse code (d) to make code longer
  28. 28.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(18));
  29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 3));
  30. 30.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  31. 31.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(6));
  32. 32.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(2));
  33. 33.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  34. 34.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 4));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Hello, name! (c) Hello, Zoya! (d) Zoya
  36. 36.🧰 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(6) + fee(8));
  37. 37.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 2));
  38. 38.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 2));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hello, name! (b) Arjun (c) greet (d) Hello, Arjun!
  40. 40.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));

Answer key

  1. 0
  2. Hi, Riya!
  3. 40
  4. 70
  5. 270
  6. a parameter
  7. 0
  8. a named block of code
  9. 21
  10. 50
  11. 6
  12. 56
  13. sends back a value
  14. 80
  15. Well done, Zoya!
  16. 40
  17. 320
  18. 110
  19. Hello, Riya!
  20. Well done, Riya!
  21. 340
  22. 0
  23. 100
  24. 120
  25. greet()
  26. Welcome, Riya!
  27. to reuse code
  28. 36
  29. 75
  30. 50
  31. 12
  32. 60
  33. 60
  34. 220
  35. Hello, Zoya!
  36. 80
  37. 20
  38. 190
  39. Hello, Arjun!
  40. 20

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