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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 910 · 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(15, 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 60;
    }
    show(fee(6) + fee(9));
  3. 3.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Well done, name! (b) Kabir (c) greet (d) Well done, Kabir!
  4. 4.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 2));
  5. 5.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 2));
  6. 6.🧰 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(12) + fee(2));
  7. 7.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 6));
  8. 8.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hello, Zoya! (b) Zoya (c) Hello, name! (d) greet
  9. 9.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(14));
  10. 10.🧰 What does return do in a function? (a) sends back a value (b) deletes the app (c) closes the screen (d) repeats the code
  11. 11.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir"));     (a) greet (b) Kabir (c) Hi, name! (d) Hi, Kabir!
  12. 12.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 4));
  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 40;
    }
    show(fee(7) + fee(4));
  14. 14.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(0));
  15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(2));
  16. 16.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(18));
  17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 2));
  18. 18.🧰 Why write a function? (a) to make code longer (b) to hide errors (c) to reuse code (d) to slow the app
  19. 19.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun"));     (a) Arjun (b) Well done, name! (c) greet (d) Well done, Arjun!
  20. 20.🧰 How do you run (call) a function called greet? (a) greet() (b) #greet (c) greet[] (d) run greet
  21. 21.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Well done, Zoya! (c) Zoya (d) Well done, name!
  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(9) + fee(2));
  23. 23.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
  24. 24.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(3));
  25. 25.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 3));
  26. 26.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) Hi, Aman! (c) Hi, name! (d) greet
  27. 27.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(8));
  28. 28.🧰 In function tip(bill), what is bill? (a) an event (b) a loop (c) a screen (d) a parameter
  29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(15, 4));
  30. 30.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir"));     (a) Kabir (b) greet (c) Welcome, name! (d) Welcome, Kabir!
  31. 31.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(25));
  32. 32.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 5));
  33. 33.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 5));
  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 40;
    }
    show(fee(6) + fee(7));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, name! (b) Arjun (c) greet (d) Welcome, Arjun!
  36. 36.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Riya"));     (a) Welcome, Riya! (b) greet (c) Welcome, name! (d) Riya
  37. 37.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya"));     (a) Hi, name! (b) Zoya (c) Hi, Zoya! (d) greet
  38. 38.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(37));
  39. 39.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, name! (b) Aman (c) greet (d) Hello, Aman!
  40. 40.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(19));

Answer key

  1. 90
  2. 120
  3. Well done, Kabir!
  4. 80
  5. 200
  6. 50
  7. 330
  8. Hello, Zoya!
  9. 28
  10. sends back a value
  11. Hi, Kabir!
  12. 380
  13. 40
  14. 60
  15. 60
  16. 54
  17. 160
  18. to reuse code
  19. Well done, Arjun!
  20. greet()
  21. Well done, Zoya!
  22. 60
  23. 50
  24. 60
  25. 75
  26. Hi, Aman!
  27. 16
  28. a parameter
  29. 60
  30. Welcome, Kabir!
  31. 50
  32. 300
  33. 450
  34. 80
  35. Welcome, Arjun!
  36. Welcome, Riya!
  37. Hi, Zoya!
  38. 111
  39. Hello, Aman!
  40. 38

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