App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 772 · 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) your last game level (b) a class leaderboard (c) a shared to-do list (d) photos on two devices
2. 2.💾 pop() takes off the last item. What does this code show?
   let notes = ["Sports", "Science", "Music"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Music (b) Sports (c) Science
3. 3.Which of these fits saving in the cloud? (a) a shared to-do list (b) notes to read offline (c) your last game level (d) the sound on/off setting
4. 4.💾 Which works with no internet at all? (a) a shared chat (b) data saved on the phone (c) a cloud leaderboard (d) a cloud backup
5. 5.💾 Which can hold many values in order? (a) a button (b) a single number (c) a list (d) a switch
6. 6.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.💾 What number does this code show?
   let coins = 7;
   coins = coins - 4;
   coins = coins + 2;
   show(coins);
8. 8.Which of these fits saving in the cloud? (a) a class leaderboard (b) your last game level (c) notes to read offline (d) a draft you are typing
9. 9.True or false: notes to read offline fits saving on the phone. (a) True (b) False
10. 10.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Zoya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Zoya (c) Riya (d) Meera
11. 11.💾 What number does this code show?
    let friends = ["Aman", "Kabir", "Arjun"];
    friends.push("Riya");
    show(friends.length);
12. 12.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
13. 13.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
14. 14.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Aman", "Riya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Meera (c) Aman (d) Riya
15. 15.💾 What number does this code show?
    let score = 6;
    score = score - 6;
    score = score + 4;
    show(score);
16. 16.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
17. 17.💾 What is a variable? (a) a picture (b) a named box for a value (c) a phone setting (d) a type of screen
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.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) in the cloud (b) on the phone
20. 20.💾 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
21. 21.💾 What number does this code show?
    let coins = 7;
    coins = coins - 1;
    coins = coins + 4;
    show(coins);
22. 22.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) you send a message (c) the app is closed (d) the screen turns off
23. 23.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
24. 24.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Arjun", "Zoya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Meera (c) Zoya (d) Kabir
25. 25.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Arjun", "Meera", "Kabir", "Zoya"];
    show(friends[3]); (a) Arjun (b) Meera (c) Aman (d) Kabir
26. 26.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
27. 27.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
28. 28.💾 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
29. 29.Which of these fits saving on the phone? (a) a class leaderboard (b) a draft you are typing (c) chat messages to friends (d) a shared to-do list
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Rain", "Ocean", "Sunrise", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Sunrise (c) Rain (d) Kites
31. 31.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
32. 32.Which of these fits saving on the phone? (a) a class leaderboard (b) a shared to-do list (c) photos on two devices (d) notes to read offline
33. 33.💾 What number does this code show?
    let notes = ["Maths", "Music", "Sports"];
    notes.push("Science");
    notes.push("Art");
    show(notes.length);
34. 34.💾 What number does this code show?
    let songs = ["Ocean", "Sunrise"];
    songs.push("Stars");
    show(songs.length);
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Stars", "Rain", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Rain (c) Ocean (d) Stars
36. 36.💾 What number does this code show?
    let notes = ["Hindi", "Maths"];
    notes.push("Art");
    notes.push("Music");
    show(notes.length);
37. 37.💾 What number does this code show?
    let coins = 3;
    coins = coins - 1;
    coins = coins + 4;
    show(coins);
38. 38.💾 What number does this code show?
    let notes = ["Science", "Maths", "Music", "Art"];
    notes.push("Sports");
    show(notes.length);
39. 39.💾 What number does this code show?
    let songs = ["Rain", "Monsoon", "Ocean"];
    songs.push("Sunrise");
    songs.push("Kites");
    show(songs.length);
40. 40.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Music", "Sports"];
    show(notes[0]); (a) Sports (b) Music (c) Art (d) Science

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