App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 715 · 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: the sound on/off setting fits saving in the cloud. (a) False (b) True
2. 2.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a class leaderboard (d) a draft you are typing
3. 3.💾 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
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 does this code show? (Positions start at 0.)
   let friends = ["Kabir", "Meera", "Aman", "Zoya"];
   show(friends[2]); (a) Aman (b) Meera (c) Kabir (d) Zoya
6. 6.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
8. 8.💾 pop() takes off the last item. What does this code show?
   let songs = ["Stars", "Sunrise", "Monsoon", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Kites (b) Monsoon (c) Stars (d) Sunrise
9. 9.💾 What does this code show? (Positions start at 0.)
   let friends = ["Arjun", "Meera", "Riya", "Zoya"];
   show(friends[0]); (a) Meera (b) Zoya (c) Riya (d) Arjun
10. 10.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the phone is lost (c) you send a message (d) the app is closed
11. 11.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
12. 12.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Ocean", "Monsoon", "Stars"];
    show(songs[1]); (a) Rain (b) Monsoon (c) Ocean (d) Stars
13. 13.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) in the cloud (b) on the phone
14. 14.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Sunrise", "Rain"];
    show(songs[1]); (a) Rain (b) Monsoon (c) Sunrise
15. 15.💾 What number does this code show?
    let friends = ["Meera", "Kabir", "Riya"];
    friends.push("Zoya");
    show(friends.length);
16. 16.Which of these fits saving in the cloud? (a) chat messages to friends (b) the sound on/off setting (c) notes to read offline (d) your last game level
17. 17.💾 What number does this code show?
    let coins = 4;
    coins = coins - 3;
    coins = coins + 3;
    show(coins);
18. 18.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
19. 19.💾 What is a variable? (a) a type of screen (b) a named box for a value (c) a phone setting (d) a picture
20. 20.True or false: your last game level fits saving in the cloud. (a) True (b) False
21. 21.💾 What number does this code show?
    let notes = ["Music", "Art", "Science"];
    notes.push("Hindi");
    notes.push("Maths");
    show(notes.length);
22. 22.💾 What number does this code show?
    let score = 5;
    score = score - 4;
    score = score + 5;
    show(score);
23. 23.💾 What number does this code show?
    let songs = ["Stars", "Rain"];
    songs.push("Ocean");
    show(songs.length);
24. 24.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Meera", "Aman"];
    show(friends[0]); (a) Riya (b) Meera (c) Aman
25. 25.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 0 (d) 1
26. 26.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
27. 27.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a shared to-do list (d) a draft you are typing
28. 28.💾 What number does this code show?
    let friends = ["Riya", "Meera"];
    friends.push("Zoya");
    show(friends.length);
29. 29.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
30. 30.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Science", "Hindi", "Art", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Science (d) Hindi
31. 31.💾 What number does this code show?
    let notes = ["Art", "Maths", "Hindi", "Science"];
    notes.push("Music");
    show(notes.length);
32. 32.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) use it on any device (d) skip the internet
33. 33.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
34. 34.💾 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
35. 35.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Meera", "Zoya", "Kabir"];
    show(friends[0]); (a) Aman (b) Riya (c) Meera (d) Zoya
36. 36.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Maths", "Sports", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Science (c) Sports (d) Maths
37. 37.💾 What number does this code show?
    let songs = ["Sunrise", "Kites"];
    songs.push("Rain");
    show(songs.length);
38. 38.💾 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
39. 39.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
40. 40.💾 What number does this code show?
    let points = 4;
    points = points - 4;
    points = points + 1;
    show(points);

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