App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 108 · 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 of these fits saving on the phone? (a) the sound on/off setting (b) a class leaderboard (c) photos on two devices (d) chat messages to friends
2. 2.💾 What does this code show? (Positions start at 0.)
   let friends = ["Kabir", "Aman", "Zoya", "Riya", "Arjun"];
   show(friends[3]); (a) Kabir (b) Zoya (c) Riya (d) Aman
3. 3.💾 What number does this code show?
   let songs = ["Sunrise", "Monsoon", "Kites"];
   songs.push("Rain");
   songs.push("Stars");
   show(songs.length);
4. 4.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
5. 5.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
6. 6.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) a shared to-do list (d) notes to read offline
7. 7.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
8. 8.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
10. 10.Which of these fits saving in the cloud? (a) your last game level (b) a class leaderboard (c) a draft you are typing (d) the sound on/off setting
11. 11.💾 Where should the app save photos on two devices: 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 = 3;
    stars = stars - 3;
    stars = stars + 1;
    show(stars);
13. 13.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
14. 14.💾 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
15. 15.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
16. 16.💾 What number does this code show?
    let coins = 5;
    coins = coins - 1;
    coins = coins + 2;
    show(coins);
17. 17.True or false: your last game level fits saving on the phone. (a) False (b) True
18. 18.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Stars", "Ocean", "Kites", "Monsoon"];
    show(songs[4]); (a) Sunrise (b) Monsoon (c) Stars (d) Ocean
19. 19.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
20. 20.💾 What number does this code show?
    let points = 7;
    points = points - 2;
    points = points + 2;
    show(points);
21. 21.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
22. 22.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) a shared chat (d) data saved on the phone
23. 23.💾 What number does this code show?
    let friends = ["Zoya", "Kabir", "Riya", "Arjun"];
    friends.push("Meera");
    show(friends.length);
24. 24.💾 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
25. 25.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
26. 26.💾 Which can hold many values in order? (a) a list (b) a button (c) a single number (d) a switch
27. 27.💾 What number does this code show?
    let score = 3;
    score = score - 2;
    score = score + 3;
    show(score);
28. 28.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
29. 29.💾 What is a variable? (a) a picture (b) a type of screen (c) a named box for a value (d) a phone setting
30. 30.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the phone is lost (d) the screen turns off
31. 31.True or false: photos on two devices fits saving on the phone. (a) False (b) True
32. 32.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
33. 33.💾 What number does this code show?
    let friends = ["Riya", "Aman"];
    friends.push("Meera");
    friends.push("Arjun");
    show(friends.length);
34. 34.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Sports", "Art", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Sports (c) Art (d) Science
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Ocean", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Ocean (c) Monsoon
36. 36.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Science", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Sports (c) Science
37. 37.Which of these fits saving in the cloud? (a) a shared to-do list (b) your last game level (c) a draft you are typing (d) notes to read offline
38. 38.💾 What number does this code show?
    let notes = ["Music", "Maths", "Science"];
    notes.push("Art");
    notes.push("Hindi");
    show(notes.length);
39. 39.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Zoya", "Riya"];
    show(friends[1]); (a) Riya (b) Zoya (c) Kabir
40. 40.💾 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

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