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App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 65 · 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 songs = ["Kites", "Ocean", "Stars", "Monsoon"];
    songs.push("Rain");
    show(songs.length);
  2. 2.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a picture (d) a type of screen
  3. 3.💾 What number does this code show?
    let score = 6;
    score = score - 1;
    score = score + 1;
    show(score);
  4. 4.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud leaderboard (c) a cloud backup (d) a shared chat
  5. 5.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) never need a password (d) use it on any device
  6. 6.💾 What number does this code show?
    let score = 7;
    score = score - 6;
    score = score + 4;
    show(score);
  7. 7.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the phone is lost (c) you send a message (d) the screen turns off
  8. 8.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) the sound on/off setting (d) a shared to-do list
  9. 9.💾 What number does this code show?
    let score = 9;
    score = score - 9;
    score = score + 3;
    show(score);
  10. 10.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
  11. 11.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
  12. 12.Which of these fits saving on the phone? (a) a class leaderboard (b) notes to read offline (c) photos on two devices (d) chat messages to friends
  13. 13.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Kabir", "Arjun", "Riya", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Riya (b) Arjun (c) Aman (d) Kabir
  14. 14.💾 What number does this code show?
    let lives = 8;
    lives = lives - 7;
    lives = lives + 4;
    show(lives);
  15. 15.💾 What number does this code show?
    let songs = ["Monsoon", "Rain", "Sunrise"];
    songs.push("Stars");
    songs.push("Kites");
    show(songs.length);
  16. 16.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) in the cloud (b) on the phone
  17. 17.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
  18. 18.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Rain", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Monsoon (b) Sunrise (c) Rain
  19. 19.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Sports", "Maths", "Science", "Hindi"];
    show(notes[4]);     (a) Maths (b) Hindi (c) Sports (d) Music
  20. 20.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
  21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Arjun", "Aman", "Riya"];
    show(friends[1]);     (a) Meera (b) Kabir (c) Aman (d) Arjun
  22. 22.Which of these fits saving on the phone? (a) a shared to-do list (b) a draft you are typing (c) a class leaderboard (d) chat messages to friends
  23. 23.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a shared to-do list (d) your last game level
  24. 24.💾 What number does this code show?
    let points = 5;
    points = points - 4;
    points = points + 3;
    show(points);
  25. 25.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Sunrise", "Kites", "Monsoon", "Rain"];
    show(songs[4]);     (a) Kites (b) Rain (c) Ocean (d) Sunrise
  26. 26.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Science", "Music"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Science (b) Maths (c) Music
  27. 27.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
  28. 28.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
  29. 29.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
  30. 30.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Art", "Science", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Science (b) Art (c) Hindi (d) Maths
  31. 31.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) photos on two devices (d) your last game level
  32. 32.True or false: notes to read offline fits saving on the phone. (a) True (b) False
  33. 33.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
  34. 34.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Kabir (b) Aman (c) Meera
  35. 35.💾 What number does this code show?
    let friends = ["Aman", "Zoya", "Meera", "Riya"];
    friends.push("Arjun");
    friends.push("Kabir");
    show(friends.length);
  36. 36.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Monsoon", "Stars", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Kites (b) Monsoon (c) Rain (d) Stars
  37. 37.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Riya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Aman (b) Riya (c) Arjun
  38. 38.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
  39. 39.💾 What number does this code show?
    let songs = ["Sunrise", "Stars", "Rain", "Kites"];
    songs.push("Ocean");
    songs.push("Monsoon");
    show(songs.length);
  40. 40.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Stars", "Ocean", "Sunrise"];
    show(songs[4]);     (a) Monsoon (b) Rain (c) Stars (d) Sunrise

Answer key

  1. 5
  2. a named box for a value
  3. 6
  4. data saved on the phone
  5. use it on any device
  6. 5
  7. the phone is lost
  8. the sound on/off setting
  9. 3
  10. on the phone
  11. in the cloud
  12. notes to read offline
  13. Riya
  14. 5
  15. 5
  16. on the phone
  17. False
  18. Rain
  19. Hindi
  20. in the cloud
  21. Meera
  22. a draft you are typing
  23. your last game level
  24. 4
  25. Rain
  26. Science
  27. in the cloud
  28. True
  29. True
  30. Science
  31. photos on two devices
  32. True
  33. False
  34. Kabir
  35. 6
  36. Stars
  37. Riya
  38. False
  39. 6
  40. Sunrise

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