App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 91 · 40 questions

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.

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

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