App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 949 · 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 chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
2. 2.True or false: your last game level fits saving in the cloud. (a) True (b) False
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Rain", "Kites", "Sunrise"];
   show(songs[1]); (a) Sunrise (b) Rain (c) Kites
4. 4.True or false: your last game level fits saving on the phone. (a) True (b) False
5. 5.💾 pop() takes off the last item. What does this code show?
   let songs = ["Stars", "Kites", "Sunrise"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Kites (b) Stars (c) Sunrise
6. 6.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) the sound on/off setting (d) a class leaderboard
7. 7.Which of these fits saving in the cloud? (a) notes to read offline (b) a shared to-do list (c) the sound on/off setting (d) your last game level
8. 8.💾 What number does this code show?
   let notes = ["Maths", "Music", "Sports"];
   notes.push("Hindi");
   show(notes.length);
9. 9.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Hindi", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Hindi
10. 10.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
11. 11.💾 What number does this code show?
    let notes = ["Sports", "Hindi"];
    notes.push("Art");
    show(notes.length);
12. 12.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Rain"];
    show(songs[2]); (a) Kites (b) Sunrise (c) Rain
13. 13.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Aman", "Riya", "Meera", "Zoya"];
    show(friends[1]); (a) Arjun (b) Riya (c) Aman (d) Meera
14. 14.💾 What is a variable? (a) a type of screen (b) a picture (c) a phone setting (d) a named box for a value
15. 15.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
16. 16.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud backup (c) a shared chat (d) a cloud leaderboard
17. 17.💾 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
18. 18.Which of these fits saving on the phone? (a) chat messages to friends (b) a shared to-do list (c) your last game level (d) photos on two devices
19. 19.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) chat messages to friends (d) the sound on/off setting
20. 20.Which of these fits saving in the cloud? (a) notes to read offline (b) photos on two devices (c) a draft you are typing (d) your last game level
21. 21.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Kites", "Rain", "Sunrise", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Stars (d) Rain
22. 22.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Meera", "Arjun", "Kabir", "Aman"];
    show(friends[2]); (a) Arjun (b) Kabir (c) Zoya (d) Meera
23. 23.💾 What number does this code show?
    let friends = ["Meera", "Arjun", "Aman"];
    friends.push("Kabir");
    friends.push("Zoya");
    show(friends.length);
24. 24.💾 What number does this code show?
    let notes = ["Maths", "Hindi"];
    notes.push("Music");
    notes.push("Science");
    show(notes.length);
25. 25.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Science", "Music"];
    show(notes[1]); (a) Art (b) Music (c) Science (d) Hindi
26. 26.💾 What number does this code show?
    let songs = ["Monsoon", "Stars", "Kites"];
    songs.push("Sunrise");
    songs.push("Ocean");
    show(songs.length);
27. 27.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
28. 28.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
29. 29.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) notes to read offline (d) a class leaderboard
30. 30.💾 What number does this code show?
    let songs = ["Rain", "Sunrise"];
    songs.push("Ocean");
    show(songs.length);
31. 31.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
32. 32.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Stars", "Sunrise", "Monsoon", "Rain"];
    show(songs[0]); (a) Monsoon (b) Ocean (c) Sunrise (d) Stars
33. 33.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Monsoon", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Ocean (c) Sunrise
34. 34.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
35. 35.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Hindi", "Maths"];
    show(notes[2]); (a) Hindi (b) Art (c) Music (d) Maths
36. 36.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Sports", "Maths", "Hindi"];
    show(notes[1]); (a) Science (b) Hindi (c) Sports (d) Maths
37. 37.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
38. 38.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the phone is lost (c) the app is closed (d) the screen turns off
39. 39.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) skip the internet (d) use it on any device
40. 40.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Meera", "Riya"];
    show(friends[0]); (a) Meera (b) Riya (c) Arjun

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