App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 675 · 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.💾 pop() takes off the last item. What does this code show?
   let friends = ["Riya", "Arjun", "Zoya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Zoya (b) Arjun (c) Riya
2. 2.💾 What number does this code show?
   let coins = 8;
   coins = coins - 5;
   coins = coins + 1;
   show(coins);
3. 3.💾 What number does this code show?
   let notes = ["Sports", "Maths", "Science", "Music"];
   notes.push("Hindi");
   show(notes.length);
4. 4.💾 What number does this code show?
   let points = 8;
   points = points - 6;
   points = points + 4;
   show(points);
5. 5.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
6. 6.💾 What number does this code show?
   let songs = ["Rain", "Stars", "Ocean", "Sunrise"];
   songs.push("Monsoon");
   songs.push("Kites");
   show(songs.length);
7. 7.💾 What does this code show? (Positions start at 0.)
   let friends = ["Riya", "Kabir", "Meera"];
   show(friends[1]); (a) Meera (b) Riya (c) Kabir
8. 8.💾 What is a variable? (a) a type of screen (b) a phone setting (c) a picture (d) a named box for a value
9. 9.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
11. 11.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Maths", "Music", "Art"];
    show(notes[1]); (a) Hindi (b) Art (c) Music (d) Maths
12. 12.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) a shared to-do list (d) notes to read offline
13. 13.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Meera", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Meera (c) Kabir
14. 14.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Kites", "Ocean", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Sunrise (c) Kites (d) Rain
15. 15.💾 What number does this code show?
    let songs = ["Sunrise", "Ocean", "Rain"];
    songs.push("Stars");
    show(songs.length);
16. 16.💾 What number does this code show?
    let songs = ["Monsoon", "Kites", "Stars", "Sunrise"];
    songs.push("Rain");
    songs.push("Ocean");
    show(songs.length);
17. 17.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Kabir", "Arjun"];
    show(friends[2]); (a) Aman (b) Kabir (c) Arjun
18. 18.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Music", "Hindi"];
    show(notes[0]); (a) Art (b) Science (c) Music (d) Hindi
19. 19.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
20. 20.💾 What number does this code show?
    let songs = ["Ocean", "Kites", "Rain", "Sunrise"];
    songs.push("Monsoon");
    show(songs.length);
21. 21.Which of these fits saving on the phone? (a) a draft you are typing (b) a shared to-do list (c) chat messages to friends (d) a class leaderboard
22. 22.💾 What number does this code show?
    let friends = ["Kabir", "Aman", "Arjun", "Zoya"];
    friends.push("Riya");
    show(friends.length);
23. 23.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the phone is lost (c) you send a message (d) the screen turns off
24. 24.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
25. 25.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
26. 26.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
27. 27.💾 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
28. 28.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
29. 29.💾 Which works with no internet at all? (a) a shared chat (b) a cloud backup (c) data saved on the phone (d) a cloud leaderboard
30. 30.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
31. 31.💾 What number does this code show?
    let songs = ["Stars", "Kites"];
    songs.push("Monsoon");
    show(songs.length);
32. 32.💾 What number does this code show?
    let friends = ["Riya", "Arjun", "Zoya"];
    friends.push("Kabir");
    friends.push("Aman");
    show(friends.length);
33. 33.💾 What number does this code show?
    let points = 8;
    points = points - 1;
    points = points + 1;
    show(points);
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.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) your last game level (d) a class leaderboard
36. 36.True or false: your last game level fits saving on the phone. (a) False (b) True
37. 37.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
38. 38.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 2;
    show(coins);
39. 39.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
40. 40.💾 What number does this code show?
    let notes = ["Sports", "Art", "Science", "Music"];
    notes.push("Maths");
    notes.push("Hindi");
    show(notes.length);

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