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App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 860 · 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 notes = ["Music", "Science", "Maths"];
    show(notes[0]);     (a) Music (b) Maths (c) Science
  2. 2.💾 What number does this code show?
    let friends = ["Zoya", "Aman"];
    friends.push("Riya");
    show(friends.length);
  3. 3.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) never need a password (c) shrink the app (d) use it on any device
  4. 4.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Sunrise", "Stars", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Monsoon (b) Stars (c) Sunrise (d) Ocean
  5. 5.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a list (d) a button
  6. 6.💾 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
  7. 7.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
  8. 8.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
  9. 9.True or false: notes to read offline fits saving on the phone. (a) False (b) True
  10. 10.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Science", "Maths"];
    show(notes[1]);     (a) Maths (b) Art (c) Science
  11. 11.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Ocean", "Kites", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Monsoon (b) Kites (c) Stars (d) Ocean
  12. 12.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Music", "Art"];
    show(notes[0]);     (a) Maths (b) Art (c) Music
  13. 13.💾 What number does this code show?
    let songs = ["Sunrise", "Rain", "Stars"];
    songs.push("Monsoon");
    songs.push("Ocean");
    show(songs.length);
  14. 14.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
  15. 15.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
  16. 16.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Kites (b) Stars (c) Sunrise (d) Ocean
  17. 17.💾 Which works with no internet at all? (a) a shared chat (b) a cloud leaderboard (c) a cloud backup (d) data saved on the phone
  18. 18.💾 What number does this code show?
    let points = 7;
    points = points - 2;
    points = points + 1;
    show(points);
  19. 19.💾 What is a variable? (a) a type of screen (b) a picture (c) a phone setting (d) a named box for a value
  20. 20.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Stars", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Kites (b) Stars (c) Sunrise
  21. 21.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Kites", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Kites (b) Stars (c) Rain
  22. 22.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a draft you are typing (d) a class leaderboard
  23. 23.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Zoya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Zoya (b) Meera (c) Aman
  24. 24.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
  25. 25.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Aman", "Arjun"];
    show(friends[0]);     (a) Aman (b) Zoya (c) Arjun
  26. 26.💾 What number does this code show?
    let stars = 3;
    stars = stars - 1;
    stars = stars + 3;
    show(stars);
  27. 27.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 10 (d) 0
  28. 28.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
  29. 29.💾 What number does this code show?
    let notes = ["Music", "Art", "Science", "Maths"];
    notes.push("Hindi");
    notes.push("Sports");
    show(notes.length);
  30. 30.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Maths", "Hindi", "Music"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Art (b) Maths (c) Hindi (d) Music
  31. 31.💾 What number does this code show?
    let points = 3;
    points = points - 2;
    points = points + 3;
    show(points);
  32. 32.💾 What number does this code show?
    let notes = ["Music", "Art", "Maths"];
    notes.push("Sports");
    notes.push("Hindi");
    show(notes.length);
  33. 33.💾 What number does this code show?
    let friends = ["Kabir", "Riya"];
    friends.push("Zoya");
    friends.push("Meera");
    show(friends.length);
  34. 34.💾 What number does this code show?
    let friends = ["Aman", "Kabir"];
    friends.push("Riya");
    friends.push("Arjun");
    show(friends.length);
  35. 35.💾 What number does this code show?
    let coins = 4;
    coins = coins - 3;
    coins = coins + 1;
    show(coins);
  36. 36.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the screen turns off (d) the phone is lost
  37. 37.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Meera", "Arjun"];
    show(friends[0]);     (a) Meera (b) Zoya (c) Arjun
  38. 38.💾 What number does this code show?
    let friends = ["Kabir", "Meera", "Aman"];
    friends.push("Zoya");
    show(friends.length);
  39. 39.💾 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
  40. 40.💾 What number does this code show?
    let score = 8;
    score = score - 3;
    score = score + 1;
    show(score);

Answer key

  1. Music
  2. 3
  3. use it on any device
  4. Stars
  5. a list
  6. on the phone
  7. on the phone
  8. True
  9. True
  10. Science
  11. Kites
  12. Maths
  13. 5
  14. in the cloud
  15. False
  16. Ocean
  17. data saved on the phone
  18. 6
  19. a named box for a value
  20. Stars
  21. Kites
  22. a draft you are typing
  23. Zoya
  24. False
  25. Zoya
  26. 5
  27. 0
  28. True
  29. 6
  30. Hindi
  31. 4
  32. 5
  33. 4
  34. 4
  35. 2
  36. the phone is lost
  37. Zoya
  38. 4
  39. on the phone
  40. 6

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