App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 619 · 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.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
2. 2.💾 What does this code show? (Positions start at 0.)
   let friends = ["Arjun", "Kabir", "Zoya", "Riya", "Aman"];
   show(friends[1]); (a) Kabir (b) Riya (c) Zoya (d) Arjun
3. 3.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) a shared to-do list (d) notes to read offline
4. 4.💾 What number does this code show?
   let stars = 5;
   stars = stars - 2;
   stars = stars + 1;
   show(stars);
5. 5.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the phone is lost (c) the screen turns off (d) the app is closed
6. 6.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.Which of these fits saving in the cloud? (a) a class leaderboard (b) your last game level (c) the sound on/off setting (d) a draft you are typing
8. 8.💾 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
9. 9.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) never need a password (d) shrink the app
10. 10.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
11. 11.💾 What is a variable? (a) a picture (b) a type of screen (c) a named box for a value (d) a phone setting
12. 12.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
13. 13.💾 What number does this code show?
    let notes = ["Sports", "Maths"];
    notes.push("Art");
    notes.push("Hindi");
    show(notes.length);
14. 14.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
15. 15.Which of these fits saving on the phone? (a) photos on two devices (b) the sound on/off setting (c) a shared to-do list (d) a class leaderboard
16. 16.💾 What number does this code show?
    let stars = 4;
    stars = stars - 2;
    stars = stars + 3;
    show(stars);
17. 17.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Ocean", "Kites", "Stars", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Ocean (c) Kites (d) Sunrise
18. 18.💾 What number does this code show?
    let points = 4;
    points = points - 1;
    points = points + 2;
    show(points);
19. 19.Which of these fits saving on the phone? (a) a class leaderboard (b) a shared to-do list (c) your last game level (d) chat messages to friends
20. 20.💾 What number does this code show?
    let friends = ["Arjun", "Riya", "Kabir"];
    friends.push("Aman");
    show(friends.length);
21. 21.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Riya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Meera (c) Aman
22. 22.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Sports", "Music", "Hindi", "Science"];
    show(notes[3]); (a) Sports (b) Art (c) Hindi (d) Music
23. 23.💾 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
24. 24.💾 What number does this code show?
    let stars = 5;
    stars = stars - 5;
    stars = stars + 1;
    show(stars);
25. 25.💾 What number does this code show?
    let songs = ["Kites", "Stars", "Rain", "Ocean"];
    songs.push("Monsoon");
    songs.push("Sunrise");
    show(songs.length);
26. 26.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
27. 27.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Stars", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Sunrise (c) Kites
28. 28.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.💾 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
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Sunrise", "Kites", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Kites (c) Monsoon (d) Sunrise
31. 31.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
32. 32.💾 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
33. 33.True or false: notes to read offline fits saving on the phone. (a) True (b) False
34. 34.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Arjun", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Aman (c) Riya (d) Kabir
35. 35.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Arjun", "Kabir", "Riya"];
    show(friends[2]); (a) Arjun (b) Kabir (c) Riya (d) Zoya
36. 36.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
37. 37.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
38. 38.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Arjun", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Arjun (c) Meera
39. 39.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Aman", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Aman (c) Riya
40. 40.True or false: photos on two devices fits saving in the cloud. (a) True (b) False

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