App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 246 · 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.💾 What does this code show? (Positions start at 0.)
   let songs = ["Kites", "Rain", "Monsoon", "Stars", "Sunrise"];
   show(songs[3]); (a) Stars (b) Rain (c) Kites (d) Monsoon
2. 2.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
3. 3.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Zoya", "Meera"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Meera (b) Zoya (c) Aman
4. 4.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
5. 5.💾 Which can hold many values in order? (a) a button (b) a single number (c) a list (d) a switch
6. 6.Which of these fits saving in the cloud? (a) notes to read offline (b) a class leaderboard (c) the sound on/off setting (d) your last game level
7. 7.Which of these fits saving on the phone? (a) the sound on/off setting (b) photos on two devices (c) a shared to-do list (d) chat messages to friends
8. 8.💾 What does this code show? (Positions start at 0.)
   let notes = ["Hindi", "Science", "Art"];
   show(notes[0]); (a) Art (b) Science (c) Hindi
9. 9.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
10. 10.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
11. 11.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
12. 12.💾 What number does this code show?
    let stars = 3;
    stars = stars - 2;
    stars = stars + 1;
    show(stars);
13. 13.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
14. 14.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
15. 15.💾 What number does this code show?
    let coins = 9;
    coins = coins - 9;
    coins = coins + 5;
    show(coins);
16. 16.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) your last game level (d) a class leaderboard
17. 17.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud leaderboard (c) a cloud backup (d) a shared chat
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Arjun", "Riya", "Aman"];
    show(friends[4]); (a) Meera (b) Kabir (c) Aman (d) Arjun
19. 19.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Monsoon", "Stars", "Sunrise", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Ocean (c) Stars (d) Sunrise
20. 20.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) skip the internet (c) never need a password (d) use it on any device
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Meera", "Arjun", "Zoya"];
    show(friends[0]); (a) Meera (b) Zoya (c) Aman (d) Arjun
22. 22.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Hindi", "Music", "Sports", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Science (c) Hindi (d) Sports
23. 23.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) photos on two devices (d) a draft you are typing
24. 24.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
25. 25.💾 What number does this code show?
    let songs = ["Kites", "Stars", "Monsoon", "Rain"];
    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.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
28. 28.Which of these fits saving on the phone? (a) chat messages to friends (b) notes to read offline (c) photos on two devices (d) a class leaderboard
29. 29.💾 What number does this code show?
    let friends = ["Meera", "Riya"];
    friends.push("Aman");
    friends.push("Arjun");
    show(friends.length);
30. 30.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Kabir", "Aman", "Arjun", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Arjun (d) Kabir
31. 31.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Meera", "Riya", "Kabir"];
    show(friends[0]); (a) Kabir (b) Meera (c) Zoya (d) Riya
32. 32.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
33. 33.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
34. 34.💾 What number does this code show?
    let songs = ["Ocean", "Kites", "Monsoon"];
    songs.push("Rain");
    songs.push("Sunrise");
    show(songs.length);
35. 35.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) chat messages to friends (d) notes to read offline
36. 36.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Music", "Maths", "Hindi", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Maths (c) Hindi (d) Music
37. 37.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 0 (d) 10
38. 38.💾 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
39. 39.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
40. 40.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Sports", "Art"];
    show(notes[2]); (a) Music (b) Sports (c) Art

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