App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 458 · 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 does this code show? (Positions start at 0.)
   let friends = ["Aman", "Kabir", "Meera", "Zoya", "Arjun"];
   show(friends[3]); (a) Aman (b) Kabir (c) Meera (d) Zoya
2. 2.💾 pop() takes off the last item. What does this code show?
   let songs = ["Sunrise", "Ocean", "Monsoon"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Ocean (b) Sunrise (c) Monsoon
3. 3.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
5. 5.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.💾 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
7. 7.True or false: notes to read offline fits saving on the phone. (a) False (b) True
8. 8.Which of these fits saving on the phone? (a) the sound on/off setting (b) chat messages to friends (c) a shared to-do list (d) a class leaderboard
9. 9.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
10. 10.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
11. 11.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Rain", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Monsoon (c) Sunrise
12. 12.💾 Which can hold many values in order? (a) a list (b) a single number (c) a button (d) a switch
13. 13.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Kabir
14. 14.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the app is closed (c) the screen turns off (d) you send a message
15. 15.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
16. 16.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Hindi", "Sports", "Art", "Music"];
    show(notes[3]); (a) Art (b) Sports (c) Hindi (d) Science
17. 17.💾 What number does this code show?
    let points = 7;
    points = points - 1;
    points = points + 3;
    show(points);
18. 18.💾 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
19. 19.💾 What is a variable? (a) a picture (b) a type of screen (c) a named box for a value (d) a phone setting
20. 20.Which of these fits saving in the cloud? (a) your last game level (b) chat messages to friends (c) notes to read offline (d) the sound on/off setting
21. 21.💾 What number does this code show?
    let lives = 4;
    lives = lives - 1;
    lives = lives + 4;
    show(lives);
22. 22.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
23. 23.💾 What number does this code show?
    let friends = ["Aman", "Meera", "Riya", "Zoya"];
    friends.push("Kabir");
    show(friends.length);
24. 24.💾 What number does this code show?
    let songs = ["Rain", "Kites"];
    songs.push("Ocean");
    songs.push("Sunrise");
    show(songs.length);
25. 25.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
26. 26.Which of these fits saving in the cloud? (a) a shared to-do list (b) a draft you are typing (c) notes to read offline (d) the sound on/off setting
27. 27.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Sunrise", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Sunrise (c) Rain
28. 28.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
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) photos on two devices
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Sports", "Hindi", "Maths"];
    show(notes[1]); (a) Sports (b) Science (c) Maths (d) Hindi
31. 31.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
32. 32.💾 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
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Maths", "Hindi", "Science"];
    show(notes[0]); (a) Hindi (b) Sports (c) Maths (d) Science
34. 34.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
35. 35.💾 What number does this code show?
    let notes = ["Music", "Hindi", "Art", "Maths"];
    notes.push("Sports");
    show(notes.length);
36. 36.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
37. 37.💾 What number does this code show?
    let songs = ["Rain", "Sunrise", "Stars", "Monsoon"];
    songs.push("Ocean");
    songs.push("Kites");
    show(songs.length);
38. 38.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
39. 39.Which of these fits saving on the phone? (a) a shared to-do list (b) your last game level (c) photos on two devices (d) chat messages to friends
40. 40.💾 What number does this code show?
    let notes = ["Art", "Sports"];
    notes.push("Maths");
    show(notes.length);

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