App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 495 · 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 draft you are typing (b) a class leaderboard (c) chat messages to friends (d) photos on two devices
2. 2.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 1 (c) 10 (d) 2
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Rain", "Ocean", "Stars", "Sunrise"];
   show(songs[3]); (a) Stars (b) Ocean (c) Sunrise (d) Rain
4. 4.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
5. 5.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) notes to read offline (d) a class leaderboard
6. 6.💾 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
7. 7.💾 What is a variable? (a) a phone setting (b) a picture (c) a named box for a value (d) a type of screen
8. 8.💾 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
9. 9.💾 pop() takes off the last item. What does this code show?
   let notes = ["Art", "Sports", "Music", "Hindi"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Hindi (b) Sports (c) Music (d) Art
10. 10.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
11. 11.💾 What number does this code show?
    let score = 4;
    score = score - 3;
    score = score + 2;
    show(score);
12. 12.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
13. 13.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Ocean", "Rain", "Monsoon", "Stars"];
    show(songs[4]); (a) Rain (b) Stars (c) Ocean (d) Kites
14. 14.💾 What number does this code show?
    let songs = ["Ocean", "Stars"];
    songs.push("Rain");
    show(songs.length);
15. 15.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Aman", "Zoya"];
    show(friends[0]); (a) Aman (b) Riya (c) Zoya
16. 16.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) use it on any device (d) never need a password
17. 17.True or false: your last game level fits saving in the cloud. (a) True (b) False
18. 18.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
19. 19.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Art", "Music", "Science"];
    show(notes[4]); (a) Science (b) Art (c) Maths (d) Sports
20. 20.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a class leaderboard (d) the sound on/off setting
21. 21.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
22. 22.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Hindi", "Sports", "Music"];
    show(notes[0]); (a) Art (b) Hindi (c) Sports (d) Science
23. 23.True or false: notes to read offline fits saving on the phone. (a) True (b) False
24. 24.💾 What number does this code show?
    let songs = ["Sunrise", "Kites", "Stars"];
    songs.push("Ocean");
    show(songs.length);
25. 25.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Maths"];
    show(notes[2]); (a) Maths (b) Art (c) Science
26. 26.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
27. 27.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Monsoon", "Rain", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Monsoon (c) Sunrise (d) Stars
28. 28.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Stars", "Monsoon", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Sunrise (c) Monsoon (d) Stars
29. 29.💾 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
30. 30.Which of these fits saving on the phone? (a) a class leaderboard (b) notes to read offline (c) a shared to-do list (d) chat messages to friends
31. 31.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
32. 32.💾 What number does this code show?
    let friends = ["Kabir", "Meera"];
    friends.push("Aman");
    show(friends.length);
33. 33.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Zoya", "Riya", "Arjun", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Riya (c) Zoya (d) Arjun
34. 34.💾 What number does this code show?
    let points = 3;
    points = points - 2;
    points = points + 1;
    show(points);
35. 35.💾 What number does this code show?
    let songs = ["Sunrise", "Kites", "Rain"];
    songs.push("Stars");
    show(songs.length);
36. 36.💾 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
37. 37.Which of these fits saving on the phone? (a) a class leaderboard (b) your last game level (c) photos on two devices (d) chat messages to friends
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Rain", "Kites", "Sunrise", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Sunrise (d) Monsoon
39. 39.True or false: photos on two devices fits saving on the phone. (a) False (b) True
40. 40.💾 Which can hold many values in order? (a) a single number (b) a button (c) a list (d) a switch

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