App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 682 · 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 can hold many values in order? (a) a list (b) a switch (c) a button (d) a single number
2. 2.💾 What is a variable? (a) a type of screen (b) a phone setting (c) a picture (d) a named box for a value
3. 3.💾 What does this code show? (Positions start at 0.)
   let friends = ["Riya", "Zoya", "Kabir", "Meera"];
   show(friends[2]); (a) Meera (b) Kabir (c) Riya (d) Zoya
4. 4.Which of these fits saving on the phone? (a) chat messages to friends (b) your last game level (c) a shared to-do list (d) a class leaderboard
5. 5.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 1 (d) 10
6. 6.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
8. 8.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
9. 9.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
11. 11.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Sunrise", "Kites", "Rain"];
    show(songs[3]); (a) Rain (b) Sunrise (c) Kites (d) Stars
13. 13.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Science", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Science (c) Art
14. 14.Which of these fits saving in the cloud? (a) a shared to-do list (b) your last game level (c) the sound on/off setting (d) a draft you are typing
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 = ["Monsoon", "Rain", "Sunrise", "Stars"];
    show(songs[3]); (a) Monsoon (b) Rain (c) Sunrise (d) Stars
17. 17.💾 What number does this code show?
    let coins = 7;
    coins = coins - 5;
    coins = coins + 1;
    show(coins);
18. 18.💾 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
19. 19.💾 What number does this code show?
    let points = 7;
    points = points - 1;
    points = points + 3;
    show(points);
20. 20.💾 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
21. 21.True or false: your last game level fits saving in the cloud. (a) False (b) True
22. 22.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
23. 23.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Music", "Sports", "Maths", "Science"];
    show(notes[1]); (a) Maths (b) Hindi (c) Sports (d) Music
24. 24.💾 What number does this code show?
    let songs = ["Rain", "Sunrise", "Ocean"];
    songs.push("Stars");
    songs.push("Kites");
    show(songs.length);
25. 25.💾 What number does this code show?
    let songs = ["Sunrise", "Ocean", "Stars"];
    songs.push("Kites");
    show(songs.length);
26. 26.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Ocean", "Sunrise", "Rain"];
    show(songs[3]); (a) Ocean (b) Stars (c) Sunrise (d) Rain
28. 28.💾 What number does this code show?
    let lives = 3;
    lives = lives - 3;
    lives = lives + 4;
    show(lives);
29. 29.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) a shared to-do list (d) chat messages to friends
30. 30.💾 What number does this code show?
    let score = 8;
    score = score - 2;
    score = score + 5;
    show(score);
31. 31.Which of these fits saving in the cloud? (a) notes to read offline (b) chat messages to friends (c) your last game level (d) the sound on/off setting
32. 32.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Kites", "Sunrise"];
    show(songs[1]); (a) Rain (b) Sunrise (c) Kites
33. 33.💾 Which works with no internet at all? (a) a shared chat (b) a cloud backup (c) a cloud leaderboard (d) data saved on the phone
34. 34.💾 What number does this code show?
    let songs = ["Stars", "Sunrise"];
    songs.push("Rain");
    songs.push("Ocean");
    show(songs.length);
35. 35.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Sports", "Art"];
    show(notes[0]); (a) Art (b) Music (c) Sports
36. 36.💾 What number does this code show?
    let coins = 5;
    coins = coins - 1;
    coins = coins + 5;
    show(coins);
37. 37.💾 What number does this code show?
    let points = 3;
    points = points - 3;
    points = points + 3;
    show(points);
38. 38.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Zoya", "Meera", "Arjun", "Kabir"];
    show(friends[0]); (a) Aman (b) Arjun (c) Meera (d) Zoya
39. 39.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Maths", "Science"];
    show(notes[3]); (a) Maths (b) Hindi (c) Art (d) Science
40. 40.True or false: a draft you are typing fits saving on the phone. (a) False (b) True

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