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App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 978 · 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 stars = 8;
    stars = stars - 2;
    stars = stars + 1;
    show(stars);
  2. 2.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 0 (d) 1
  3. 3.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
  4. 4.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
  5. 5.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) the sound on/off setting (d) a class leaderboard
  6. 6.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Hindi", "Science", "Music", "Art"];
    show(notes[0]);     (a) Music (b) Sports (c) Hindi (d) Science
  7. 7.💾 What number does this code show?
    let score = 5;
    score = score - 1;
    score = score + 2;
    show(score);
  8. 8.💾 What is a variable? (a) a type of screen (b) a picture (c) a phone setting (d) a named box for a value
  9. 9.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Kabir", "Meera"];
    show(friends[0]);     (a) Kabir (b) Aman (c) Meera
  10. 10.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the phone is lost (c) the screen turns off (d) the app is closed
  11. 11.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Sports", "Maths", "Science"];
    show(notes[1]);     (a) Science (b) Music (c) Maths (d) Sports
  12. 12.💾 What number does this code show?
    let notes = ["Hindi", "Maths", "Sports", "Science"];
    notes.push("Art");
    notes.push("Music");
    show(notes.length);
  13. 13.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
  14. 14.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Music", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Maths (b) Sports (c) Music
  15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Maths", "Science", "Sports"];
    show(notes[0]);     (a) Hindi (b) Science (c) Art (d) Maths
  16. 16.Which of these fits saving on the phone? (a) a class leaderboard (b) notes to read offline (c) a shared to-do list (d) chat messages to friends
  17. 17.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) on the phone (b) in the cloud
  18. 18.Which of these fits saving on the phone? (a) your last game level (b) a class leaderboard (c) photos on two devices (d) chat messages to friends
  19. 19.💾 What number does this code show?
    let notes = ["Maths", "Music"];
    notes.push("Art");
    notes.push("Sports");
    show(notes.length);
  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.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
  22. 22.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
  23. 23.True or false: notes to read offline fits saving on the phone. (a) True (b) False
  24. 24.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) on the phone (b) in the cloud
  25. 25.💾 What number does this code show?
    let score = 3;
    score = score - 2;
    score = score + 5;
    show(score);
  26. 26.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Sunrise", "Kites", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Kites (b) Sunrise (c) Stars (d) Monsoon
  27. 27.💾 Which works with no internet at all? (a) a cloud backup (b) a shared chat (c) data saved on the phone (d) a cloud leaderboard
  28. 28.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Kabir", "Arjun", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Riya (b) Aman (c) Kabir (d) Arjun
  29. 29.💾 What number does this code show?
    let stars = 3;
    stars = stars - 1;
    stars = stars + 3;
    show(stars);
  30. 30.💾 What number does this code show?
    let friends = ["Meera", "Kabir", "Arjun"];
    friends.push("Riya");
    friends.push("Zoya");
    show(friends.length);
  31. 31.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
  32. 32.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) never need a password (d) shrink the app
  33. 33.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Sports", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Hindi (b) Maths (c) Sports
  34. 34.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Maths", "Science"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Hindi (b) Art (c) Science (d) Maths
  35. 35.💾 What number does this code show?
    let notes = ["Art", "Sports"];
    notes.push("Music");
    show(notes.length);
  36. 36.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Stars", "Rain", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Stars (b) Kites (c) Rain (d) Sunrise
  37. 37.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a shared to-do list (c) your last game level (d) a draft you are typing
  38. 38.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Ocean", "Monsoon"];
    show(songs[0]);     (a) Ocean (b) Monsoon (c) Rain
  39. 39.True or false: your last game level fits saving on the phone. (a) True (b) False
  40. 40.💾 What number does this code show?
    let score = 6;
    score = score - 2;
    score = score + 3;
    show(score);

Answer key

  1. 7
  2. 0
  3. on the phone
  4. False
  5. the sound on/off setting
  6. Sports
  7. 6
  8. a named box for a value
  9. Aman
  10. the phone is lost
  11. Sports
  12. 6
  13. in the cloud
  14. Music
  15. Art
  16. notes to read offline
  17. in the cloud
  18. your last game level
  19. 4
  20. in the cloud
  21. False
  22. on the phone
  23. True
  24. on the phone
  25. 6
  26. Kites
  27. data saved on the phone
  28. Arjun
  29. 5
  30. 5
  31. True
  32. use it on any device
  33. Sports
  34. Maths
  35. 3
  36. Rain
  37. a shared to-do list
  38. Rain
  39. True
  40. 7

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