App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 10 · 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.💾 What number does this code show?
   let notes = ["Maths", "Sports", "Science", "Music"];
   notes.push("Hindi");
   show(notes.length);
2. 2.Which of these fits saving in the cloud? (a) a draft you are typing (b) chat messages to friends (c) notes to read offline (d) your last game level
3. 3.Which of these fits saving on the phone? (a) photos on two devices (b) the sound on/off setting (c) a shared to-do list (d) a class leaderboard
4. 4.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) shrink the app (d) never need a password
5. 5.💾 pop() takes off the last item. What does this code show?
   let songs = ["Rain", "Ocean", "Stars", "Kites", "Sunrise"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Rain (b) Ocean (c) Stars (d) Kites
6. 6.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a class leaderboard (c) notes to read offline (d) a draft you are typing
7. 7.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Hindi", "Maths", "Science", "Art"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Maths (b) Hindi (c) Music (d) Science
8. 8.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) photos on two devices (d) notes to read offline
9. 9.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
10. 10.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
11. 11.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
13. 13.💾 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
14. 14.True or false: your last game level fits saving in the cloud. (a) True (b) False
15. 15.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
16. 16.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
17. 17.💾 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
18. 18.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Aman", "Zoya", "Riya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Zoya (d) Arjun
19. 19.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Maths", "Hindi", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Science (c) Music (d) Hindi
20. 20.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) data saved on the phone (d) a shared chat
21. 21.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
22. 22.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
23. 23.💾 What number does this code show?
    let notes = ["Art", "Hindi"];
    notes.push("Science");
    notes.push("Music");
    show(notes.length);
24. 24.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Zoya", "Kabir", "Meera", "Arjun"];
    show(friends[1]); (a) Kabir (b) Riya (c) Zoya (d) Meera
25. 25.💾 What number does this code show?
    let coins = 9;
    coins = coins - 1;
    coins = coins + 1;
    show(coins);
26. 26.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Maths", "Art"];
    show(notes[0]); (a) Art (b) Maths (c) Sports
27. 27.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
28. 28.💾 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
29. 29.💾 What number does this code show?
    let notes = ["Sports", "Maths", "Science", "Art"];
    notes.push("Music");
    notes.push("Hindi");
    show(notes.length);
30. 30.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Stars", "Kites", "Sunrise", "Rain"];
    show(songs[1]); (a) Sunrise (b) Monsoon (c) Kites (d) Stars
31. 31.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Kabir", "Arjun", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Arjun (d) Kabir
32. 32.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) your last game level (d) chat messages to friends
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Hindi", "Sports", "Maths"];
    show(notes[1]); (a) Hindi (b) Art (c) Sports (d) Science
34. 34.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Arjun", "Riya", "Kabir", "Meera"];
    show(friends[2]); (a) Arjun (b) Riya (c) Kabir (d) Zoya
35. 35.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Sports", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Science
36. 36.💾 What number does this code show?
    let songs = ["Monsoon", "Sunrise", "Rain", "Stars"];
    songs.push("Kites");
    songs.push("Ocean");
    show(songs.length);
37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Sports", "Science", "Music"];
    show(notes[2]); (a) Sports (b) Hindi (c) Music (d) Science
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Rain", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Monsoon
39. 39.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
40. 40.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 2 (d) 0

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