App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 159 · 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.💾 pop() takes off the last item. What does this code show?
   let notes = ["Art", "Music", "Hindi", "Science", "Maths"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Hindi (b) Science (c) Music (d) Art
2. 2.💾 pop() takes off the last item. What does this code show?
   let songs = ["Ocean", "Sunrise", "Rain", "Monsoon"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Rain (b) Sunrise (c) Monsoon (d) Ocean
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Stars", "Kites", "Rain", "Sunrise"];
   show(songs[1]); (a) Kites (b) Ocean (c) Rain (d) Stars
4. 4.💾 What does this code show? (Positions start at 0.)
   let notes = ["Sports", "Music", "Maths"];
   show(notes[2]); (a) Maths (b) Sports (c) Music
5. 5.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
6. 6.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) the sound on/off setting (d) a shared to-do list
7. 7.💾 What does this code show? (Positions start at 0.)
   let friends = ["Kabir", "Zoya", "Aman"];
   show(friends[2]); (a) Zoya (b) Kabir (c) Aman
8. 8.True or false: notes to read offline fits saving on the phone. (a) True (b) False
9. 9.💾 Which can hold many values in order? (a) a list (b) a button (c) a single number (d) a switch
10. 10.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) on the phone (b) in the cloud
11. 11.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Sports", "Science", "Hindi", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Sports (c) Art (d) Science
12. 12.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Zoya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Riya (c) Zoya
13. 13.💾 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
14. 14.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a class leaderboard (d) your last game level
15. 15.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) your last game level (d) photos on two devices
16. 16.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
17. 17.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 0 (d) 2
18. 18.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
19. 19.💾 What number does this code show?
    let points = 3;
    points = points - 3;
    points = points + 2;
    show(points);
20. 20.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Arjun", "Kabir", "Meera"];
    show(friends[0]); (a) Zoya (b) Kabir (c) Arjun (d) Meera
22. 22.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Sunrise", "Stars", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Stars (c) Sunrise (d) Monsoon
23. 23.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
24. 24.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Sports", "Art"];
    show(notes[0]); (a) Art (b) Hindi (c) Sports
25. 25.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
26. 26.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a class leaderboard (d) notes to read offline
27. 27.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Sports"];
    show(notes[2]); (a) Maths (b) Art (c) Sports
28. 28.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Maths", "Art", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Music (c) Hindi (d) Maths
29. 29.Which of these fits saving on the phone? (a) your last game level (b) chat messages to friends (c) a shared to-do list (d) a class leaderboard
30. 30.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Kites", "Sunrise"];
    show(songs[1]); (a) Sunrise (b) Monsoon (c) Kites
31. 31.True or false: photos on two devices fits saving on the phone. (a) True (b) False
32. 32.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Kabir", "Meera"];
    show(friends[0]); (a) Arjun (b) Meera (c) Kabir
33. 33.💾 What number does this code show?
    let coins = 6;
    coins = coins - 3;
    coins = coins + 1;
    show(coins);
34. 34.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Hindi", "Science"];
    show(notes[0]); (a) Maths (b) Hindi (c) Science
35. 35.💾 What number does this code show?
    let friends = ["Riya", "Arjun"];
    friends.push("Kabir");
    show(friends.length);
36. 36.💾 What number does this code show?
    let friends = ["Arjun", "Meera"];
    friends.push("Riya");
    friends.push("Zoya");
    show(friends.length);
37. 37.💾 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
38. 38.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
39. 39.💾 What number does this code show?
    let score = 9;
    score = score - 4;
    score = score + 3;
    show(score);
40. 40.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False

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