App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 378 · 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 songs = ["Monsoon", "Rain", "Stars"];
   songs.push("Kites");
   show(songs.length);
2. 2.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a shared to-do list (d) the sound on/off setting
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Kites", "Stars"];
   show(songs[0]); (a) Kites (b) Stars (c) Ocean
4. 4.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) photos on two devices (d) chat messages to friends
5. 5.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Art", "Maths", "Sports", "Hindi"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Maths (b) Art (c) Sports (d) Music
6. 6.💾 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
7. 7.💾 pop() takes off the last item. What does this code show?
   let friends = ["Arjun", "Zoya", "Kabir", "Riya", "Meera"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Arjun (b) Riya (c) Kabir (d) Zoya
8. 8.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
9. 9.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) your last game level (d) photos on two devices
10. 10.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
11. 11.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
12. 12.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
13. 13.Which of these fits saving in the cloud? (a) photos on two devices (b) a draft you are typing (c) the sound on/off setting (d) your last game level
14. 14.💾 What number does this code show?
    let stars = 3;
    stars = stars - 2;
    stars = stars + 1;
    show(stars);
15. 15.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) the sound on/off setting (d) chat messages to friends
16. 16.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) a shared to-do list (d) the sound on/off setting
17. 17.💾 Which can hold many values in order? (a) a button (b) a list (c) a single number (d) a switch
18. 18.💾 What number does this code show?
    let points = 3;
    points = points - 2;
    points = points + 2;
    show(points);
19. 19.💾 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
20. 20.💾 What is a variable? (a) a named box for a value (b) a type of screen (c) a phone setting (d) a picture
21. 21.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Zoya", "Arjun", "Riya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Arjun (d) Zoya
22. 22.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Music", "Hindi"];
    show(notes[2]); (a) Music (b) Art (c) Hindi (d) Maths
23. 23.💾 Which works with no internet at all? (a) a cloud backup (b) data saved on the phone (c) a shared chat (d) a cloud leaderboard
24. 24.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Ocean", "Kites", "Stars", "Rain"];
    show(songs[1]); (a) Ocean (b) Kites (c) Stars (d) Sunrise
25. 25.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Hindi", "Maths"];
    show(notes[1]); (a) Hindi (b) Science (c) Maths
26. 26.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Arjun", "Zoya"];
    show(friends[2]); (a) Zoya (b) Arjun (c) Aman (d) Riya
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Ocean", "Sunrise"];
    show(songs[1]); (a) Stars (b) Ocean (c) Sunrise
28. 28.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Kabir", "Arjun", "Meera"];
    show(friends[0]); (a) Arjun (b) Aman (c) Kabir (d) Meera
29. 29.Which of these fits saving on the phone? (a) a draft you are typing (b) a shared to-do list (c) chat messages to friends (d) photos on two devices
30. 30.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Arjun"];
    show(friends[2]); (a) Meera (b) Arjun (c) Kabir
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 songs = ["Monsoon", "Ocean", "Stars"];
    show(songs[0]); (a) Ocean (b) Stars (c) Monsoon
33. 33.💾 What number does this code show?
    let stars = 6;
    stars = stars - 1;
    stars = stars + 5;
    show(stars);
34. 34.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
35. 35.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Stars"];
    show(songs[1]); (a) Monsoon (b) Kites (c) Stars
36. 36.💾 What number does this code show?
    let stars = 3;
    stars = stars - 1;
    stars = stars + 3;
    show(stars);
37. 37.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 2 (c) 0 (d) 1
38. 38.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
39. 39.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
40. 40.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud

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