App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 283 · 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) photos on two devices (b) chat messages to friends (c) a class leaderboard (d) notes to read offline
2. 2.💾 What does this code show? (Positions start at 0.)
   let songs = ["Kites", "Ocean", "Rain", "Sunrise", "Stars"];
   show(songs[2]); (a) Sunrise (b) Ocean (c) Rain (d) Kites
3. 3.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) photos on two devices
4. 4.💾 What does this code show? (Positions start at 0.)
   let friends = ["Kabir", "Zoya", "Meera", "Arjun", "Aman"];
   show(friends[1]); (a) Kabir (b) Meera (c) Arjun (d) Zoya
5. 5.Which of these fits saving in the cloud? (a) a draft you are typing (b) chat messages to friends (c) the sound on/off setting (d) your last game level
6. 6.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.💾 Which works with no internet at all? (a) a cloud leaderboard (b) data saved on the phone (c) a shared chat (d) a cloud backup
8. 8.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
9. 9.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Art", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Art (b) Sports (c) Maths
10. 10.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
11. 11.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Stars", "Kites", "Sunrise"];
    show(songs[1]); (a) Sunrise (b) Kites (c) Rain (d) Stars
12. 12.💾 What number does this code show?
    let notes = ["Maths", "Sports", "Art"];
    notes.push("Hindi");
    notes.push("Music");
    show(notes.length);
13. 13.💾 What number does this code show?
    let score = 6;
    score = score - 5;
    score = score + 4;
    show(score);
14. 14.💾 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
15. 15.💾 What number does this code show?
    let score = 4;
    score = score - 3;
    score = score + 5;
    show(score);
16. 16.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Rain", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Sunrise (c) Rain (d) Ocean
17. 17.Which of these fits saving in the cloud? (a) a class leaderboard (b) notes to read offline (c) a draft you are typing (d) the sound on/off setting
18. 18.Which of these fits saving on the phone? (a) your last game level (b) photos on two devices (c) chat messages to friends (d) a shared to-do list
19. 19.💾 What number does this code show?
    let songs = ["Stars", "Ocean", "Kites"];
    songs.push("Rain");
    songs.push("Sunrise");
    show(songs.length);
20. 20.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
21. 21.💾 What number does this code show?
    let stars = 7;
    stars = stars - 5;
    stars = stars + 4;
    show(stars);
22. 22.💾 What number does this code show?
    let notes = ["Hindi", "Sports", "Science", "Music"];
    notes.push("Art");
    show(notes.length);
23. 23.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a list (d) a button
24. 24.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Ocean", "Stars"];
    show(songs[1]); (a) Ocean (b) Monsoon (c) Stars
25. 25.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
26. 26.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
27. 27.Which of these fits saving in the cloud? (a) a draft you are typing (b) a shared to-do list (c) notes to read offline (d) your last game level
28. 28.Which of these fits saving on the phone? (a) the sound on/off setting (b) photos on two devices (c) a shared to-do list (d) a class leaderboard
29. 29.💾 What number does this code show?
    let coins = 6;
    coins = coins - 5;
    coins = coins + 4;
    show(coins);
30. 30.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
31. 31.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Riya (c) Aman
32. 32.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Science", "Maths"];
    show(notes[0]); (a) Science (b) Maths (c) Art (d) Hindi
33. 33.💾 What number does this code show?
    let songs = ["Stars", "Rain"];
    songs.push("Sunrise");
    songs.push("Monsoon");
    show(songs.length);
34. 34.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
35. 35.💾 What number does this code show?
    let score = 9;
    score = score - 3;
    score = score + 1;
    show(score);
36. 36.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
37. 37.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
38. 38.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Stars"];
    show(songs[0]); (a) Kites (b) Sunrise (c) Stars
39. 39.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 0 (d) 10
40. 40.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the phone is lost (d) the screen turns off

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