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App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 202 · 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 notes = ["Hindi", "Sports", "Art", "Science"];
    notes.push("Maths");
    notes.push("Music");
    show(notes.length);
  2. 2.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
  3. 3.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
  4. 4.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
  5. 5.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Kabir", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Aman (b) Zoya (c) Kabir
  6. 6.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a class leaderboard (d) notes to read offline
  7. 7.💾 What number does this code show?
    let songs = ["Kites", "Rain"];
    songs.push("Stars");
    show(songs.length);
  8. 8.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Arjun", "Meera", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Kabir (b) Aman (c) Arjun (d) Meera
  9. 9.💾 What number does this code show?
    let friends = ["Arjun", "Riya"];
    friends.push("Zoya");
    friends.push("Meera");
    show(friends.length);
  10. 10.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Kabir", "Zoya", "Arjun"];
    show(friends[0]);     (a) Kabir (b) Arjun (c) Meera (d) Zoya
  11. 11.💾 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
  12. 12.True or false: photos on two devices fits saving on the phone. (a) True (b) False
  13. 13.Which of these fits saving in the cloud? (a) a class leaderboard (b) a draft you are typing (c) the sound on/off setting (d) notes to read offline
  14. 14.Which of these fits saving in the cloud? (a) notes to read offline (b) chat messages to friends (c) the sound on/off setting (d) your last game level
  15. 15.💾 What number does this code show?
    let score = 7;
    score = score - 5;
    score = score + 2;
    show(score);
  16. 16.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
  17. 17.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Aman", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Zoya (b) Kabir (c) Aman
  18. 18.💾 What number does this code show?
    let songs = ["Monsoon", "Kites", "Ocean"];
    songs.push("Sunrise");
    songs.push("Rain");
    show(songs.length);
  19. 19.💾 What number does this code show?
    let lives = 6;
    lives = lives - 2;
    lives = lives + 2;
    show(lives);
  20. 20.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
  21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Meera", "Kabir"];
    show(friends[1]);     (a) Riya (b) Kabir (c) Meera
  22. 22.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
  23. 23.💾 What is a variable? (a) a picture (b) a type of screen (c) a named box for a value (d) a phone setting
  24. 24.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Music", "Hindi"];
    show(notes[0]);     (a) Music (b) Maths (c) Hindi
  25. 25.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Maths", "Science"];
    show(notes[1]);     (a) Science (b) Maths (c) Sports
  26. 26.True or false: your last game level fits saving in the cloud. (a) True (b) False
  27. 27.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Kabir", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Kabir (b) Riya (c) Arjun
  28. 28.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) your last game level (d) a shared to-do list
  29. 29.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a draft you are typing (d) photos on two devices
  30. 30.💾 What number does this code show?
    let songs = ["Rain", "Ocean", "Stars", "Sunrise"];
    songs.push("Kites");
    songs.push("Monsoon");
    show(songs.length);
  31. 31.💾 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
  32. 32.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
  33. 33.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Meera", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Aman (b) Kabir (c) Meera (d) Riya
  34. 34.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Science", "Art", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Art (b) Hindi (c) Sports (d) Science
  35. 35.💾 Which can hold many values in order? (a) a single number (b) a switch (c) a list (d) a button
  36. 36.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Kites", "Ocean", "Stars"];
    show(songs[2]);     (a) Ocean (b) Stars (c) Kites (d) Rain
  37. 37.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Ocean", "Monsoon", "Sunrise"];
    show(songs[0]);     (a) Monsoon (b) Sunrise (c) Stars (d) Ocean
  38. 38.💾 What number does this code show?
    let notes = ["Music", "Art"];
    notes.push("Hindi");
    notes.push("Science");
    show(notes.length);
  39. 39.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Maths", "Sports", "Science", "Art"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Maths (b) Music (c) Science (d) Sports
  40. 40.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) a shared to-do list (d) a draft you are typing

Answer key

  1. 6
  2. True
  3. True
  4. False
  5. Kabir
  6. notes to read offline
  7. 3
  8. Meera
  9. 4
  10. Meera
  11. on the phone
  12. False
  13. a class leaderboard
  14. chat messages to friends
  15. 4
  16. False
  17. Aman
  18. 5
  19. 6
  20. in the cloud
  21. Meera
  22. True
  23. a named box for a value
  24. Maths
  25. Maths
  26. False
  27. Kabir
  28. a shared to-do list
  29. photos on two devices
  30. 6
  31. on the phone
  32. False
  33. Meera
  34. Art
  35. a list
  36. Ocean
  37. Stars
  38. 4
  39. Science
  40. a draft you are typing

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