App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 101 · 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) a shared to-do list (b) chat messages to friends (c) a draft you are typing (d) a class leaderboard
2. 2.💾 pop() takes off the last item. What does this code show?
   let songs = ["Rain", "Sunrise", "Ocean"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Sunrise
3. 3.💾 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
4. 4.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
5. 5.💾 What number does this code show?
   let stars = 9;
   stars = stars - 4;
   stars = stars + 4;
   show(stars);
6. 6.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the screen turns off (d) the phone is lost
7. 7.💾 Which can hold many values in order? (a) a button (b) a single number (c) a list (d) a switch
8. 8.True or false: your last game level fits saving in the cloud. (a) True (b) False
9. 9.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
10. 10.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Zoya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Aman (c) Meera
11. 11.💾 What number does this code show?
    let songs = ["Sunrise", "Rain"];
    songs.push("Stars");
    songs.push("Kites");
    show(songs.length);
12. 12.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
13. 13.💾 What number does this code show?
    let notes = ["Sports", "Maths"];
    notes.push("Music");
    show(notes.length);
14. 14.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Music", "Science"];
    show(notes[1]); (a) Science (b) Hindi (c) Music
15. 15.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Kabir", "Aman", "Riya", "Zoya"];
    show(friends[3]); (a) Aman (b) Kabir (c) Arjun (d) Riya
16. 16.True or false: photos on two devices fits saving on the phone. (a) False (b) True
17. 17.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
18. 18.True or false: your last game level fits saving on the phone. (a) True (b) False
19. 19.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) chat messages to friends
20. 20.💾 What number does this code show?
    let notes = ["Music", "Maths"];
    notes.push("Hindi");
    show(notes.length);
21. 21.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Monsoon", "Stars", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Rain (c) Stars (d) Ocean
22. 22.💾 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
23. 23.💾 What number does this code show?
    let friends = ["Meera", "Riya", "Arjun", "Aman"];
    friends.push("Kabir");
    friends.push("Zoya");
    show(friends.length);
24. 24.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 10 (d) 1
25. 25.💾 What is a variable? (a) a named box for a value (b) a phone setting (c) a type of screen (d) a picture
26. 26.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Maths", "Music", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Sports (d) Music
27. 27.💾 What number does this code show?
    let friends = ["Riya", "Meera", "Aman"];
    friends.push("Zoya");
    show(friends.length);
28. 28.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Art", "Hindi", "Maths"];
    show(notes[2]); (a) Music (b) Maths (c) Hindi (d) Art
29. 29.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Hindi", "Art", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Maths (d) Sports
30. 30.💾 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
31. 31.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
32. 32.💾 What number does this code show?
    let notes = ["Art", "Music", "Science", "Hindi"];
    notes.push("Sports");
    show(notes.length);
33. 33.💾 What number does this code show?
    let points = 3;
    points = points - 1;
    points = points + 3;
    show(points);
34. 34.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) a shared to-do list (d) your last game level
35. 35.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
36. 36.💾 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
37. 37.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Rain", "Stars", "Sunrise", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Sunrise (c) Stars (d) Ocean
38. 38.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
39. 39.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Kites", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Kites (c) Rain

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