App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 109 · 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 of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) the sound on/off setting (d) chat messages to friends
2. 2.💾 What does this code show? (Positions start at 0.)
   let friends = ["Zoya", "Aman", "Kabir", "Riya"];
   show(friends[3]); (a) Kabir (b) Riya (c) Aman (d) Zoya
3. 3.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
4. 4.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
5. 5.💾 What is a variable? (a) a phone setting (b) a picture (c) a named box for a value (d) a type of screen
6. 6.Which of these fits saving on the phone? (a) a shared to-do list (b) a draft you are typing (c) a class leaderboard (d) chat messages to friends
7. 7.💾 What number does this code show?
   let lives = 7;
   lives = lives - 4;
   lives = lives + 2;
   show(lives);
8. 8.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) photos on two devices (d) a draft you are typing
9. 9.Which of these fits saving on the phone? (a) chat messages to friends (b) notes to read offline (c) a class leaderboard (d) photos on two devices
10. 10.💾 Which can hold many values in order? (a) a list (b) a switch (c) a button (d) a single number
11. 11.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Sunrise", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Rain (c) Sunrise
12. 12.True or false: your last game level fits saving in the cloud. (a) False (b) True
13. 13.💾 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
14. 14.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
15. 15.💾 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
16. 16.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Stars", "Monsoon"];
    show(songs[2]); (a) Stars (b) Monsoon (c) Sunrise (d) Kites
17. 17.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
18. 18.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
19. 19.💾 What number does this code show?
    let points = 5;
    points = points - 4;
    points = points + 5;
    show(points);
20. 20.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Arjun", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Arjun (c) Aman
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Arjun", "Zoya", "Riya", "Meera"];
    show(friends[3]); (a) Zoya (b) Aman (c) Arjun (d) Riya
22. 22.💾 What number does this code show?
    let lives = 3;
    lives = lives - 1;
    lives = lives + 2;
    show(lives);
23. 23.💾 What number does this code show?
    let friends = ["Arjun", "Aman"];
    friends.push("Riya");
    friends.push("Kabir");
    show(friends.length);
24. 24.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
25. 25.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
26. 26.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Monsoon", "Sunrise", "Rain", "Kites"];
    show(songs[4]); (a) Ocean (b) Sunrise (c) Kites (d) Monsoon
28. 28.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Hindi", "Maths", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Sports (c) Maths (d) Hindi
29. 29.💾 What number does this code show?
    let friends = ["Arjun", "Aman", "Meera", "Zoya"];
    friends.push("Riya");
    friends.push("Kabir");
    show(friends.length);
30. 30.💾 Which works with no internet at all? (a) a shared chat (b) a cloud leaderboard (c) a cloud backup (d) data saved on the phone
31. 31.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
32. 32.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Arjun", "Kabir", "Zoya"];
    show(friends[0]); (a) Aman (b) Kabir (c) Zoya (d) Arjun
33. 33.💾 What number does this code show?
    let notes = ["Music", "Hindi"];
    notes.push("Art");
    show(notes.length);
34. 34.💾 What number does this code show?
    let songs = ["Monsoon", "Rain", "Ocean"];
    songs.push("Sunrise");
    songs.push("Kites");
    show(songs.length);
35. 35.True or false: notes to read offline fits saving on the phone. (a) True (b) False
36. 36.💾 What number does this code show?
    let score = 9;
    score = score - 2;
    score = score + 2;
    show(score);
37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Music"];
    show(notes[2]); (a) Music (b) Maths (c) Art
38. 38.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) never need a password (d) shrink the app
39. 39.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
40. 40.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Kites", "Sunrise"];
    show(songs[1]); (a) Rain (b) Kites (c) Sunrise

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