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App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 387 · 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 does this code show? (Positions start at 0.)
    let songs = ["Stars", "Rain", "Sunrise", "Kites", "Monsoon"];
    show(songs[0]);     (a) Kites (b) Stars (c) Sunrise (d) Rain
  2. 2.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Aman", "Kabir"];
    show(friends[0]);     (a) Aman (b) Riya (c) Kabir
  3. 3.💾 What number does this code show?
    let score = 5;
    score = score - 1;
    score = score + 2;
    show(score);
  4. 4.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Science", "Art", "Hindi", "Music"];
    show(notes[0]);     (a) Art (b) Sports (c) Science (d) Hindi
  5. 5.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
  6. 6.💾 Which can hold many values in order? (a) a switch (b) a list (c) a single number (d) a button
  7. 7.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
  8. 8.💾 What number does this code show?
    let coins = 5;
    coins = coins - 5;
    coins = coins + 5;
    show(coins);
  9. 9.💾 What number does this code show?
    let lives = 5;
    lives = lives - 3;
    lives = lives + 2;
    show(lives);
  10. 10.💾 What number does this code show?
    let score = 9;
    score = score - 8;
    score = score + 1;
    show(score);
  11. 11.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Art", "Music", "Hindi", "Science"];
    show(notes[4]);     (a) Sports (b) Art (c) Music (d) Science
  12. 12.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Stars", "Rain"];
    show(songs[1]);     (a) Rain (b) Stars (c) Kites
  13. 13.💾 What is a variable? (a) a named box for a value (b) a phone setting (c) a picture (d) a type of screen
  14. 14.💾 What number does this code show?
    let stars = 9;
    stars = stars - 8;
    stars = stars + 2;
    show(stars);
  15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Hindi"];
    show(notes[0]);     (a) Art (b) Hindi (c) Maths
  16. 16.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) in the cloud (b) on the phone
  17. 17.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 2 (c) 0 (d) 1
  18. 18.💾 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
  19. 19.💾 What number does this code show?
    let notes = ["Music", "Science", "Art", "Hindi"];
    notes.push("Maths");
    notes.push("Sports");
    show(notes.length);
  20. 20.Which of these fits saving in the cloud? (a) chat messages to friends (b) your last game level (c) notes to read offline (d) the sound on/off setting
  21. 21.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Music", "Sports", "Art", "Hindi"];
    show(notes[0]);     (a) Art (b) Music (c) Sports (d) Maths
  22. 22.Which of these fits saving on the phone? (a) photos on two devices (b) notes to read offline (c) a class leaderboard (d) a shared to-do list
  23. 23.💾 What number does this code show?
    let songs = ["Monsoon", "Sunrise"];
    songs.push("Ocean");
    show(songs.length);
  24. 24.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 5;
    show(score);
  25. 25.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
  26. 26.💾 What number does this code show?
    let friends = ["Aman", "Meera"];
    friends.push("Arjun");
    show(friends.length);
  27. 27.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
  28. 28.Which of these fits saving on the phone? (a) your last game level (b) a class leaderboard (c) a shared to-do list (d) chat messages to friends
  29. 29.True or false: your last game level fits saving in the cloud. (a) True (b) False
  30. 30.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Zoya", "Aman", "Riya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Aman (b) Riya (c) Arjun (d) Zoya
  31. 31.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Music", "Science"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Maths (b) Music (c) Science
  32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Aman", "Kabir", "Riya", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Kabir (b) Arjun (c) Aman (d) Riya
  33. 33.💾 What number does this code show?
    let notes = ["Sports", "Art"];
    notes.push("Science");
    notes.push("Hindi");
    show(notes.length);
  34. 34.Which of these fits saving on the phone? (a) a shared to-do list (b) a draft you are typing (c) photos on two devices (d) chat messages to friends
  35. 35.💾 What number does this code show?
    let score = 5;
    score = score - 2;
    score = score + 4;
    show(score);
  36. 36.💾 Which works with no internet at all? (a) a cloud leaderboard (b) data saved on the phone (c) a shared chat (d) a cloud backup
  37. 37.💾 What number does this code show?
    let songs = ["Rain", "Stars"];
    songs.push("Sunrise");
    songs.push("Monsoon");
    show(songs.length);
  38. 38.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Sports", "Maths", "Music", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Maths (b) Art (c) Music (d) Sports
  39. 39.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Monsoon", "Sunrise", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Ocean (b) Rain (c) Sunrise (d) Monsoon
  40. 40.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Riya", "Kabir"];
    show(friends[1]);     (a) Zoya (b) Riya (c) Kabir

Answer key

  1. Stars
  2. Riya
  3. 6
  4. Sports
  5. True
  6. a list
  7. False
  8. 5
  9. 4
  10. 2
  11. Science
  12. Stars
  13. a named box for a value
  14. 3
  15. Art
  16. on the phone
  17. 0
  18. on the phone
  19. 6
  20. chat messages to friends
  21. Maths
  22. notes to read offline
  23. 3
  24. 7
  25. True
  26. 3
  27. on the phone
  28. your last game level
  29. False
  30. Riya
  31. Music
  32. Riya
  33. 4
  34. a draft you are typing
  35. 7
  36. data saved on the phone
  37. 4
  38. Music
  39. Ocean
  40. Riya

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