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App Dev Worksheet: Functions

App development lesson 20: Functions · Set 341 · 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 does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Arjun"));     (a) Welcome, Arjun! (b) Welcome, name! (c) Arjun (d) greet
  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(1));
  3. 3.🧰 What does return do in a function? (a) sends back a value (b) deletes the app (c) closes the screen (d) repeats the code
  4. 4.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
  5. 5.🧰 What is a function? (a) a type of phone (b) a screen size (c) a named block of code (d) a list of colours
  6. 6.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(32));
  7. 7.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(8));
  8. 8.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera"));     (a) Meera (b) Hello, Meera! (c) Hello, name! (d) greet
  9. 9.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman"));     (a) Hi, name! (b) Hi, Aman! (c) greet (d) Aman
  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 20;
    }
    show(fee(4) + fee(3));
  11. 11.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(2));
  12. 12.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman"));     (a) Hello, name! (b) Hello, Aman! (c) greet (d) Aman
  13. 13.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya"));     (a) Hello, name! (b) Hello, Riya! (c) Riya (d) greet
  14. 14.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Zoya (c) Hello, Zoya! (d) Hello, name!
  15. 15.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir"));     (a) Hello, name! (b) greet (c) Kabir (d) Hello, Kabir!
  16. 16.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(3));
  17. 17.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(12));
  18. 18.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(5));
  19. 19.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 3));
  20. 20.🧰 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(3));
  21. 21.🧰 Why write a function? (a) to hide errors (b) to slow the app (c) to make code longer (d) to reuse code
  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 30;
    }
    show(fee(9) + fee(5));
  23. 23.🧰 In function tip(bill), what is bill? (a) an event (b) a loop (c) a screen (d) a parameter
  24. 24.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(13));
  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 30;
    }
    show(fee(8) + fee(6));
  26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 5));
  27. 27.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(4));
  28. 28.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(25));
  29. 29.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman"));     (a) Aman (b) greet (c) Welcome, name! (d) Welcome, Aman!
  30. 30.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 3));
  31. 31.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir"));     (a) Well done, name! (b) greet (c) Well done, Kabir! (d) Kabir
  32. 32.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 2));
  33. 33.🧰 How do you run (call) a function called greet? (a) #greet (b) greet[] (c) greet() (d) run greet
  34. 34.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(0));
  35. 35.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun"));     (a) Hi, name! (b) Arjun (c) greet (d) Hi, Arjun!
  36. 36.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera"));     (a) Hi, Meera! (b) Meera (c) Hi, name! (d) greet
  37. 37.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya"));     (a) greet (b) Well done, name! (c) Zoya (d) Well done, Zoya!
  38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));
  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(5) + fee(4));
  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 60;
    }
    show(fee(8) + fee(2));

Answer key

  1. Welcome, Arjun!
  2. 60
  3. sends back a value
  4. 22
  5. a named block of code
  6. 64
  7. 24
  8. Hello, Meera!
  9. Hi, Aman!
  10. 0
  11. 80
  12. Hello, Aman!
  13. Hello, Riya!
  14. Hello, Zoya!
  15. Hello, Kabir!
  16. 9
  17. 36
  18. 100
  19. 225
  20. 50
  21. to reuse code
  22. 60
  23. a parameter
  24. 26
  25. 60
  26. 475
  27. 100
  28. 75
  29. Welcome, Aman!
  30. 105
  31. Well done, Kabir!
  32. 110
  33. greet()
  34. 40
  35. Hi, Arjun!
  36. Hi, Meera!
  37. Well done, Zoya!
  38. 70
  39. 30
  40. 60

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