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App Dev Worksheet: Variables, Lists and Saving

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

Answer key

  1. 0
  2. False
  3. 3
  4. Monsoon
  5. False
  6. a draft you are typing
  7. Kabir
  8. on the phone
  9. Monsoon
  10. 6
  11. False
  12. False
  13. a named box for a value
  14. 5
  15. Rain
  16. Rain
  17. on the phone
  18. 5
  19. on the phone
  20. 7
  21. use it on any device
  22. a list
  23. 5
  24. Rain
  25. Zoya
  26. 4
  27. 4
  28. on the phone
  29. Art
  30. Kites
  31. 3
  32. in the cloud
  33. Zoya
  34. chat messages to friends
  35. Ocean
  36. True
  37. your last game level
  38. Monsoon
  39. Rain
  40. a class leaderboard

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