App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 236 · 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.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
2. 2.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
3. 3.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the phone is lost (c) the screen turns off (d) the app is closed
4. 4.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
5. 5.Which of these fits saving on the phone? (a) notes to read offline (b) a shared to-do list (c) a class leaderboard (d) photos on two devices
6. 6.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
7. 7.Which of these fits saving on the phone? (a) the sound on/off setting (b) a class leaderboard (c) chat messages to friends (d) photos on two devices
8. 8.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) notes to read offline (d) a class leaderboard
10. 10.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Hindi", "Maths"];
    show(notes[2]); (a) Science (b) Maths (c) Hindi
11. 11.💾 What number does this code show?
    let friends = ["Zoya", "Kabir", "Aman"];
    friends.push("Riya");
    show(friends.length);
12. 12.💾 What number does this code show?
    let points = 6;
    points = points - 4;
    points = points + 4;
    show(points);
13. 13.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Stars", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Rain (c) Stars
14. 14.💾 What number does this code show?
    let friends = ["Aman", "Arjun", "Meera"];
    friends.push("Zoya");
    show(friends.length);
15. 15.💾 Which can hold many values in order? (a) a button (b) a list (c) a single number (d) a switch
16. 16.💾 Which works with no internet at all? (a) a cloud backup (b) a shared chat (c) a cloud leaderboard (d) data saved on the phone
17. 17.💾 What number does this code show?
    let stars = 4;
    stars = stars - 2;
    stars = stars + 3;
    show(stars);
18. 18.Which of these fits saving on the phone? (a) a draft you are typing (b) chat messages to friends (c) a class leaderboard (d) a shared to-do list
19. 19.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Zoya", "Aman", "Arjun", "Kabir"];
    show(friends[3]); (a) Riya (b) Zoya (c) Aman (d) Arjun
20. 20.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
21. 21.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 0 (d) 2
22. 22.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Arjun", "Meera", "Aman"];
    show(friends[1]); (a) Aman (b) Kabir (c) Arjun (d) Meera
23. 23.💾 What number does this code show?
    let friends = ["Aman", "Riya", "Zoya"];
    friends.push("Arjun");
    friends.push("Meera");
    show(friends.length);
24. 24.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Rain", "Sunrise", "Kites", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Ocean (c) Sunrise (d) Kites
25. 25.💾 What is a variable? (a) a phone setting (b) a picture (c) a named box for a value (d) a type of screen
26. 26.💾 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
27. 27.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
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.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Science", "Music", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Maths (c) Music (d) Science
30. 30.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
31. 31.💾 What number does this code show?
    let stars = 4;
    stars = stars - 1;
    stars = stars + 1;
    show(stars);
32. 32.💾 What number does this code show?
    let friends = ["Riya", "Kabir"];
    friends.push("Aman");
    friends.push("Meera");
    show(friends.length);
33. 33.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Art", "Maths", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Hindi (c) Maths (d) Art
34. 34.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Music", "Art"];
    show(notes[2]); (a) Art (b) Music (c) Maths
35. 35.True or false: photos on two devices fits saving on the phone. (a) False (b) True
36. 36.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
37. 37.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
38. 38.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
39. 39.💾 What number does this code show?
    let songs = ["Kites", "Stars"];
    songs.push("Ocean");
    songs.push("Rain");
    show(songs.length);
40. 40.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Hindi", "Music"];
    show(notes[0]); (a) Music (b) Hindi (c) Sports

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