App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 385 · 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.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
2. 2.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
3. 3.💾 Which can hold many values in order? (a) a single number (b) a button (c) a switch (d) a list
4. 4.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) a class leaderboard (d) the sound on/off setting
5. 5.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
6. 6.💾 What number does this code show?
   let friends = ["Aman", "Riya", "Meera", "Zoya"];
   friends.push("Kabir");
   friends.push("Arjun");
   show(friends.length);
7. 7.💾 What number does this code show?
   let friends = ["Kabir", "Meera", "Arjun", "Zoya"];
   friends.push("Aman");
   show(friends.length);
8. 8.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Zoya", "Riya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Zoya
9. 9.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) on the phone (b) in the cloud
10. 10.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Stars", "Rain", "Ocean"];
    show(songs[0]); (a) Ocean (b) Rain (c) Sunrise (d) Stars
11. 11.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.💾 What number does this code show?
    let stars = 8;
    stars = stars - 4;
    stars = stars + 2;
    show(stars);
13. 13.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) photos on two devices (d) the sound on/off setting
14. 14.💾 What number does this code show?
    let songs = ["Stars", "Monsoon", "Sunrise"];
    songs.push("Kites");
    show(songs.length);
15. 15.💾 What number does this code show?
    let songs = ["Rain", "Kites", "Stars"];
    songs.push("Monsoon");
    songs.push("Ocean");
    show(songs.length);
16. 16.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) photos on two devices (d) the sound on/off setting
17. 17.💾 What number does this code show?
    let songs = ["Monsoon", "Sunrise", "Rain"];
    songs.push("Ocean");
    songs.push("Kites");
    show(songs.length);
18. 18.💾 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
19. 19.True or false: your last game level fits saving on the phone. (a) False (b) True
20. 20.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Music", "Art", "Sports", "Hindi"];
    show(notes[3]); (a) Science (b) Music (c) Art (d) Sports
21. 21.💾 Saving data in the cloud lets you ___. (a) never need a password (b) skip the internet (c) shrink the app (d) use it on any device
22. 22.💾 What number does this code show?
    let notes = ["Maths", "Art", "Hindi"];
    notes.push("Science");
    notes.push("Music");
    show(notes.length);
23. 23.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Hindi"];
    show(notes[0]); (a) Art (b) Maths (c) Hindi
24. 24.💾 What number does this code show?
    let score = 4;
    score = score - 3;
    score = score + 3;
    show(score);
25. 25.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
26. 26.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
27. 27.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
28. 28.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Sports", "Music"];
    show(notes[2]); (a) Art (b) Music (c) Hindi (d) Sports
29. 29.💾 What number does this code show?
    let friends = ["Aman", "Kabir"];
    friends.push("Riya");
    show(friends.length);
30. 30.💾 What number does this code show?
    let songs = ["Sunrise", "Stars", "Rain"];
    songs.push("Kites");
    songs.push("Ocean");
    show(songs.length);
31. 31.💾 What number does this code show?
    let score = 8;
    score = score - 6;
    score = score + 5;
    show(score);
32. 32.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a shared chat (c) data saved on the phone (d) a cloud backup
33. 33.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the screen turns off (c) the app is closed (d) the phone is lost
34. 34.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 10 (c) 2 (d) 1
35. 35.💾 What number does this code show?
    let stars = 9;
    stars = stars - 1;
    stars = stars + 5;
    show(stars);
36. 36.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Kites", "Sunrise", "Stars"];
    show(songs[3]); (a) Rain (b) Monsoon (c) Sunrise (d) Kites
37. 37.💾 What number does this code show?
    let score = 6;
    score = score - 1;
    score = score + 2;
    show(score);
38. 38.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Rain"];
    show(songs[0]); (a) Sunrise (b) Rain (c) Kites
39. 39.💾 What number does this code show?
    let notes = ["Music", "Hindi", "Maths"];
    notes.push("Science");
    notes.push("Art");
    show(notes.length);
40. 40.💾 What number does this code show?
    let notes = ["Maths", "Sports"];
    notes.push("Hindi");
    notes.push("Music");
    show(notes.length);

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