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App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 434 · 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.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) notes to read offline (d) a shared to-do list
  2. 2.Which of these fits saving in the cloud? (a) a draft you are typing (b) chat messages to friends (c) notes to read offline (d) the sound on/off setting
  3. 3.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
  4. 4.💾 What number does this code show?
    let friends = ["Kabir", "Riya", "Meera", "Aman"];
    friends.push("Arjun");
    friends.push("Zoya");
    show(friends.length);
  5. 5.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
  6. 6.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
  7. 7.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) shrink the app (c) never need a password (d) skip the internet
  8. 8.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Science", "Music"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Music (b) Art (c) Science
  9. 9.Which of these fits saving on the phone? (a) photos on two devices (b) the sound on/off setting (c) chat messages to friends (d) a class leaderboard
  10. 10.💾 What number does this code show?
    let points = 6;
    points = points - 5;
    points = points + 4;
    show(points);
  11. 11.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) chat messages to friends (d) a draft you are typing
  12. 12.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
  13. 13.💾 What number does this code show?
    let notes = ["Hindi", "Sports", "Music", "Art"];
    notes.push("Science");
    notes.push("Maths");
    show(notes.length);
  14. 14.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
  15. 15.💾 What number does this code show?
    let lives = 9;
    lives = lives - 9;
    lives = lives + 2;
    show(lives);
  16. 16.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Riya", "Kabir", "Aman", "Zoya"];
    show(friends[3]);     (a) Kabir (b) Riya (c) Aman (d) Meera
  17. 17.💾 What number does this code show?
    let songs = ["Stars", "Kites", "Ocean", "Sunrise"];
    songs.push("Monsoon");
    show(songs.length);
  18. 18.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) chat messages to friends (d) a shared to-do list
  19. 19.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
  20. 20.💾 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
  21. 21.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
  22. 22.💾 What number does this code show?
    let stars = 7;
    stars = stars - 5;
    stars = stars + 1;
    show(stars);
  23. 23.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Sports", "Science", "Hindi"];
    show(notes[1]);     (a) Art (b) Sports (c) Maths (d) Science
  24. 24.💾 What number does this code show?
    let songs = ["Stars", "Monsoon", "Sunrise"];
    songs.push("Ocean");
    show(songs.length);
  25. 25.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
  26. 26.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) your last game level (d) photos on two devices
  27. 27.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Zoya", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Arjun (b) Riya (c) Zoya
  28. 28.💾 What number does this code show?
    let songs = ["Rain", "Kites", "Ocean", "Stars"];
    songs.push("Sunrise");
    show(songs.length);
  29. 29.💾 What number does this code show?
    let notes = ["Sports", "Hindi", "Maths"];
    notes.push("Art");
    notes.push("Music");
    show(notes.length);
  30. 30.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) on the phone (b) in the cloud
  31. 31.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
  32. 32.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
  33. 33.💾 What number does this code show?
    let notes = ["Art", "Hindi", "Sports", "Science"];
    notes.push("Maths");
    notes.push("Music");
    show(notes.length);
  34. 34.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) photos on two devices (d) a draft you are typing
  35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Stars", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Sunrise (b) Stars (c) Kites
  36. 36.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Meera", "Kabir", "Zoya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Aman (b) Meera (c) Kabir (d) Zoya
  37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Sports", "Hindi", "Maths"];
    show(notes[3]);     (a) Art (b) Hindi (c) Music (d) Sports
  38. 38.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Ocean", "Kites", "Stars"];
    show(songs[2]);     (a) Rain (b) Stars (c) Kites (d) Ocean
  39. 39.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
  40. 40.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Zoya", "Riya", "Meera", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Riya (b) Meera (c) Zoya (d) Kabir

Answer key

  1. a shared to-do list
  2. chat messages to friends
  3. False
  4. 6
  5. True
  6. 0
  7. use it on any device
  8. Science
  9. the sound on/off setting
  10. 5
  11. a draft you are typing
  12. False
  13. 6
  14. on the phone
  15. 2
  16. Aman
  17. 5
  18. notes to read offline
  19. in the cloud
  20. on the phone
  21. False
  22. 3
  23. Art
  24. 4
  25. on the phone
  26. your last game level
  27. Zoya
  28. 5
  29. 5
  30. on the phone
  31. in the cloud
  32. False
  33. 6
  34. photos on two devices
  35. Stars
  36. Zoya
  37. Hindi
  38. Kites
  39. in the cloud
  40. Meera

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