App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 683 · 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.💾 Which works with no internet at all? (a) a cloud backup (b) a shared chat (c) data saved on the phone (d) a cloud leaderboard
2. 2.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Stars", "Rain", "Ocean", "Sunrise"];
   show(songs[1]); (a) Rain (b) Ocean (c) Stars (d) Sunrise
4. 4.💾 pop() takes off the last item. What does this code show?
   let notes = ["Science", "Music", "Maths", "Sports", "Art"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Maths (b) Science (c) Music (d) Sports
5. 5.💾 What number does this code show?
   let notes = ["Maths", "Hindi"];
   notes.push("Science");
   notes.push("Music");
   show(notes.length);
6. 6.💾 What number does this code show?
   let songs = ["Kites", "Rain"];
   songs.push("Monsoon");
   show(songs.length);
7. 7.💾 What is a variable? (a) a phone setting (b) a picture (c) a type of screen (d) a named box for a value
8. 8.💾 What does this code show? (Positions start at 0.)
   let friends = ["Meera", "Riya", "Arjun", "Kabir", "Aman"];
   show(friends[2]); (a) Meera (b) Kabir (c) Riya (d) Arjun
9. 9.💾 What does this code show? (Positions start at 0.)
   let notes = ["Art", "Science", "Hindi", "Maths"];
   show(notes[2]); (a) Maths (b) Hindi (c) Science (d) Art
10. 10.💾 What number does this code show?
    let stars = 9;
    stars = stars - 5;
    stars = stars + 1;
    show(stars);
11. 11.Which of these fits saving on the phone? (a) your last game level (b) photos on two devices (c) chat messages to friends (d) a shared to-do list
12. 12.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
13. 13.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Stars", "Sunrise", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Monsoon (c) Sunrise (d) Stars
14. 14.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
15. 15.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
16. 16.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
17. 17.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Science", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Music (c) Science
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Meera"];
    show(friends[0]); (a) Arjun (b) Meera (c) Riya
19. 19.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Stars", "Kites", "Monsoon"];
    show(songs[2]); (a) Ocean (b) Monsoon (c) Kites (d) Stars
20. 20.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) a class leaderboard (d) the sound on/off setting
21. 21.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
22. 22.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Kites", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Ocean
23. 23.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the screen turns off (d) the phone is lost
24. 24.Which of these fits saving in the cloud? (a) photos on two devices (b) the sound on/off setting (c) your last game level (d) a draft you are typing
25. 25.True or false: your last game level fits saving on the phone. (a) False (b) True
26. 26.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
27. 27.💾 What number does this code show?
    let songs = ["Rain", "Monsoon", "Sunrise"];
    songs.push("Ocean");
    show(songs.length);
28. 28.Which of these fits saving on the phone? (a) photos on two devices (b) notes to read offline (c) a class leaderboard (d) chat messages to friends
29. 29.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Kites", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Monsoon
31. 31.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
32. 32.💾 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
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Music"];
    show(notes[2]); (a) Music (b) Maths (c) Sports
34. 34.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) shrink the app (c) never need a password (d) skip the internet
35. 35.💾 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
36. 36.💾 What number does this code show?
    let score = 4;
    score = score - 2;
    score = score + 5;
    show(score);
37. 37.💾 Which can hold many values in order? (a) a button (b) a single number (c) a list (d) a switch
38. 38.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Meera", "Aman", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Arjun (d) Kabir
39. 39.💾 What number does this code show?
    let lives = 4;
    lives = lives - 1;
    lives = lives + 4;
    show(lives);
40. 40.True or false: chat messages to friends fits saving on the phone. (a) True (b) False

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