App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 512 · 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 = ["Ocean", "Monsoon", "Rain"];
   show(songs[2]); (a) Ocean (b) Rain (c) Monsoon
2. 2.True or false: notes to read offline fits saving on the phone. (a) False (b) True
3. 3.True or false: your last game level fits saving on the phone. (a) False (b) True
4. 4.💾 What number does this code show?
   let notes = ["Music", "Science"];
   notes.push("Sports");
   show(notes.length);
5. 5.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the phone is lost (d) the app is closed
6. 6.Which of these fits saving on the phone? (a) a class leaderboard (b) a shared to-do list (c) chat messages to friends (d) notes to read offline
7. 7.💾 What number does this code show?
   let songs = ["Kites", "Ocean"];
   songs.push("Monsoon");
   show(songs.length);
8. 8.💾 What number does this code show?
   let songs = ["Rain", "Sunrise"];
   songs.push("Kites");
   show(songs.length);
9. 9.💾 What number does this code show?
   let points = 3;
   points = points - 3;
   points = points + 1;
   show(points);
10. 10.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Ocean", "Kites", "Sunrise"];
    show(songs[2]); (a) Sunrise (b) Stars (c) Kites (d) Ocean
11. 11.💾 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
12. 12.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
13. 13.💾 What number does this code show?
    let notes = ["Art", "Maths", "Hindi", "Sports"];
    notes.push("Science");
    notes.push("Music");
    show(notes.length);
14. 14.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Music", "Maths", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Science (c) Maths (d) Art
15. 15.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
16. 16.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
17. 17.💾 What number does this code show?
    let friends = ["Kabir", "Zoya", "Arjun"];
    friends.push("Riya");
    friends.push("Meera");
    show(friends.length);
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Meera", "Kabir"];
    show(friends[1]); (a) Aman (b) Meera (c) Kabir
19. 19.💾 What number does this code show?
    let friends = ["Riya", "Arjun", "Aman"];
    friends.push("Kabir");
    show(friends.length);
20. 20.💾 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
21. 21.💾 What number does this code show?
    let score = 8;
    score = score - 4;
    score = score + 4;
    show(score);
22. 22.💾 What number does this code show?
    let notes = ["Maths", "Hindi", "Music", "Sports"];
    notes.push("Art");
    show(notes.length);
23. 23.💾 What number does this code show?
    let coins = 5;
    coins = coins - 1;
    coins = coins + 1;
    show(coins);
24. 24.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
25. 25.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Science", "Art", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Maths (c) Science (d) Art
26. 26.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Monsoon"];
    show(songs[0]); (a) Kites (b) Monsoon (c) Sunrise
27. 27.💾 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
28. 28.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) data saved on the phone (d) a shared chat
29. 29.💾 What number does this code show?
    let songs = ["Kites", "Stars", "Monsoon"];
    songs.push("Sunrise");
    show(songs.length);
30. 30.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) chat messages to friends (d) a draft you are typing
31. 31.💾 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
32. 32.True or false: photos on two devices fits saving on the phone. (a) True (b) False
33. 33.💾 What number does this code show?
    let friends = ["Arjun", "Kabir"];
    friends.push("Zoya");
    show(friends.length);
34. 34.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a shared to-do list (d) your last game level
35. 35.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) photos on two devices (d) the sound on/off setting
36. 36.Which of these fits saving in the cloud? (a) photos on two devices (b) notes to read offline (c) your last game level (d) a draft you are typing
37. 37.💾 What number does this code show?
    let notes = ["Science", "Music", "Hindi"];
    notes.push("Art");
    show(notes.length);
38. 38.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
39. 39.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
40. 40.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False

Free app development lessons, practice and worksheets at talentjr.in/app-development-for-students