← Data: variables, lists and saving lesson New set →

App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 532 · 40 questions
TalentJR

Developer's tip (Box, list, place): A variable holds one value; a list holds many in order. Positions start at 0. push adds to the end; pop takes off the last item; length is how many items. On the phone: works offline, private. In the cloud: shared, any device, needs the internet.

NameDateTime takenScore ___ / 40
  1. 1.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 2;
    show(score);
  2. 2.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
  3. 3.💾 What number does this code show?
    let points = 4;
    points = points - 1;
    points = points + 5;
    show(points);
  4. 4.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the app is closed (c) the phone is lost (d) you send a message
  5. 5.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Zoya", "Meera", "Aman", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Aman (b) Kabir (c) Meera (d) Zoya
  6. 6.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Meera", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Arjun (b) Aman (c) Meera
  7. 7.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
  8. 8.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a shared to-do list (d) your last game level
  9. 9.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Stars", "Rain", "Sunrise"];
    show(songs[3]);     (a) Kites (b) Monsoon (c) Stars (d) Rain
  10. 10.💾 Which works with no internet at all? (a) a cloud leaderboard (b) data saved on the phone (c) a shared chat (d) a cloud backup
  11. 11.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) in the cloud (b) on the phone
  12. 12.💾 What number does this code show?
    let notes = ["Hindi", "Music"];
    notes.push("Maths");
    notes.push("Sports");
    show(notes.length);
  13. 13.💾 What number does this code show?
    let coins = 4;
    coins = coins - 4;
    coins = coins + 5;
    show(coins);
  14. 14.💾 What number does this code show?
    let songs = ["Kites", "Ocean", "Monsoon"];
    songs.push("Sunrise");
    songs.push("Stars");
    show(songs.length);
  15. 15.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
  16. 16.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) notes to read offline (d) photos on two devices
  17. 17.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Ocean"];
    show(songs[2]);     (a) Sunrise (b) Ocean (c) Kites
  18. 18.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Rain", "Ocean", "Stars", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Rain (b) Ocean (c) Sunrise (d) Stars
  19. 19.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
  20. 20.Which of these fits saving on the phone? (a) a class leaderboard (b) notes to read offline (c) chat messages to friends (d) photos on two devices
  21. 21.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
  22. 22.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Riya", "Aman", "Kabir"];
    show(friends[0]);     (a) Meera (b) Riya (c) Aman (d) Kabir
  23. 23.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
  24. 24.True or false: notes to read offline fits saving on the phone. (a) False (b) True
  25. 25.💾 What number does this code show?
    let score = 4;
    score = score - 1;
    score = score + 3;
    show(score);
  26. 26.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Music"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Music (b) Maths (c) Hindi
  27. 27.💾 What number does this code show?
    let friends = ["Aman", "Riya", "Arjun"];
    friends.push("Zoya");
    friends.push("Meera");
    show(friends.length);
  28. 28.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
  29. 29.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Ocean", "Monsoon", "Kites", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Sunrise (b) Kites (c) Ocean (d) Monsoon
  30. 30.💾 What number does this code show?
    let songs = ["Stars", "Sunrise", "Rain"];
    songs.push("Monsoon");
    songs.push("Kites");
    show(songs.length);
  31. 31.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
  32. 32.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Hindi", "Science", "Art"];
    show(notes[2]);     (a) Maths (b) Art (c) Hindi (d) Science
  33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Hindi", "Music"];
    show(notes[3]);     (a) Maths (b) Art (c) Hindi (d) Music
  34. 34.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
  35. 35.💾 What number does this code show?
    let notes = ["Sports", "Maths"];
    notes.push("Music");
    show(notes.length);
  36. 36.💾 What number does this code show?
    let notes = ["Maths", "Art", "Science", "Hindi"];
    notes.push("Sports");
    notes.push("Music");
    show(notes.length);
  37. 37.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
  38. 38.True or false: your last game level fits saving in the cloud. (a) False (b) True
  39. 39.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Kites", "Sunrise", "Rain"];
    show(songs[0]);     (a) Rain (b) Sunrise (c) Stars (d) Kites
  40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Rain", "Stars", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Stars (b) Rain (c) Kites (d) Ocean

Answer key

  1. 4
  2. True
  3. 8
  4. the phone is lost
  5. Aman
  6. Meera
  7. on the phone
  8. a shared to-do list
  9. Rain
  10. data saved on the phone
  11. in the cloud
  12. 4
  13. 5
  14. 5
  15. on the phone
  16. photos on two devices
  17. Ocean
  18. Stars
  19. True
  20. notes to read offline
  21. in the cloud
  22. Meera
  23. True
  24. True
  25. 6
  26. Hindi
  27. 5
  28. False
  29. Kites
  30. 5
  31. False
  32. Science
  33. Music
  34. True
  35. 3
  36. 6
  37. 0
  38. False
  39. Stars
  40. Stars

Free app development lessons, practice and worksheets at talentjr.in/app-development-for-students