App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 569 · 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 number does this code show?
   let stars = 8;
   stars = stars - 4;
   stars = stars + 4;
   show(stars);
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.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
4. 4.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a type of screen (d) a picture
5. 5.💾 What number does this code show?
   let friends = ["Aman", "Riya"];
   friends.push("Kabir");
   friends.push("Zoya");
   show(friends.length);
6. 6.💾 What does this code show? (Positions start at 0.)
   let notes = ["Music", "Science", "Hindi", "Sports", "Maths"];
   show(notes[4]); (a) Science (b) Maths (c) Music (d) Hindi
7. 7.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
8. 8.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) a draft you are typing (d) chat messages to friends
9. 9.💾 What number does this code show?
   let notes = ["Art", "Science", "Music", "Maths"];
   notes.push("Sports");
   show(notes.length);
10. 10.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) never need a password (d) use it on any device
11. 11.💾 What number does this code show?
    let notes = ["Sports", "Hindi"];
    notes.push("Art");
    show(notes.length);
12. 12.💾 What number does this code show?
    let lives = 7;
    lives = lives - 3;
    lives = lives + 2;
    show(lives);
13. 13.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
14. 14.💾 Which can hold many values in order? (a) a button (b) a single number (c) a list (d) a switch
15. 15.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
16. 16.💾 What number does this code show?
    let points = 9;
    points = points - 4;
    points = points + 4;
    show(points);
17. 17.💾 What number does this code show?
    let friends = ["Aman", "Meera", "Zoya", "Riya"];
    friends.push("Kabir");
    friends.push("Arjun");
    show(friends.length);
18. 18.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) chat messages to friends (d) the sound on/off setting
19. 19.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Rain", "Stars", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Sunrise (c) Monsoon (d) Stars
20. 20.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
21. 21.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
22. 22.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Aman", "Zoya"];
    show(friends[2]); (a) Aman (b) Meera (c) Zoya
23. 23.Which of these fits saving on the phone? (a) your last game level (b) a shared to-do list (c) a class leaderboard (d) photos on two devices
24. 24.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the app is closed (c) you send a message (d) the screen turns off
25. 25.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Riya", "Zoya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Zoya (d) Arjun
26. 26.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Kites", "Stars"];
    show(songs[0]); (a) Stars (b) Sunrise (c) Kites
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Monsoon", "Kites", "Sunrise", "Ocean"];
    show(songs[4]); (a) Monsoon (b) Kites (c) Rain (d) Ocean
28. 28.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) photos on two devices (d) the sound on/off setting
29. 29.Which of these fits saving on the phone? (a) the sound on/off setting (b) a class leaderboard (c) chat messages to friends (d) photos on two devices
30. 30.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Rain", "Ocean", "Sunrise", "Kites"];
    show(songs[0]); (a) Stars (b) Rain (c) Sunrise (d) Ocean
31. 31.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Zoya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Meera (c) Kabir
32. 32.💾 What number does this code show?
    let songs = ["Stars", "Monsoon", "Kites"];
    songs.push("Rain");
    songs.push("Ocean");
    show(songs.length);
33. 33.True or false: photos on two devices fits saving on the phone. (a) True (b) False
34. 34.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) a shared to-do list (d) notes to read offline
35. 35.💾 What number does this code show?
    let notes = ["Science", "Art"];
    notes.push("Sports");
    notes.push("Hindi");
    show(notes.length);
36. 36.💾 What number does this code show?
    let stars = 9;
    stars = stars - 8;
    stars = stars + 2;
    show(stars);
37. 37.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
38. 38.💾 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
39. 39.💾 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
40. 40.True or false: a shared to-do list fits saving on the phone. (a) False (b) True

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