App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 389 · 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 lives = 5;
   lives = lives - 5;
   lives = lives + 4;
   show(lives);
2. 2.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
3. 3.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
4. 4.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) chat messages to friends (d) a draft you are typing
5. 5.Which of these fits saving in the cloud? (a) a shared to-do list (b) the sound on/off setting (c) a draft you are typing (d) notes to read offline
6. 6.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Sports", "Art", "Science"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Science (b) Music (c) Art (d) Sports
7. 7.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
8. 8.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.💾 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
10. 10.💾 What number does this code show?
    let lives = 5;
    lives = lives - 2;
    lives = lives + 5;
    show(lives);
11. 11.💾 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
12. 12.💾 What number does this code show?
    let songs = ["Rain", "Kites"];
    songs.push("Stars");
    show(songs.length);
13. 13.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
14. 14.Which of these fits saving on the phone? (a) chat messages to friends (b) notes to read offline (c) a class leaderboard (d) photos on two devices
15. 15.💾 What is a variable? (a) a named box for a value (b) a type of screen (c) a phone setting (d) a picture
16. 16.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
17. 17.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
18. 18.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
19. 19.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 2 (d) 0
20. 20.💾 What number does this code show?
    let lives = 5;
    lives = lives - 5;
    lives = lives + 1;
    show(lives);
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.💾 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
23. 23.💾 What number does this code show?
    let songs = ["Ocean", "Monsoon", "Kites", "Sunrise"];
    songs.push("Rain");
    songs.push("Stars");
    show(songs.length);
24. 24.💾 What number does this code show?
    let notes = ["Hindi", "Music", "Art"];
    notes.push("Sports");
    notes.push("Science");
    show(notes.length);
25. 25.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Art"];
    show(notes[1]); (a) Art (b) Maths (c) Sports
26. 26.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) data saved on the phone (d) a shared chat
27. 27.💾 What number does this code show?
    let coins = 9;
    coins = coins - 8;
    coins = coins + 1;
    show(coins);
28. 28.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
29. 29.True or false: photos on two devices fits saving on the phone. (a) False (b) True
30. 30.💾 What number does this code show?
    let notes = ["Art", "Hindi", "Science"];
    notes.push("Maths");
    show(notes.length);
31. 31.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Music", "Science", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Music (d) Science
32. 32.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) a class leaderboard (d) notes to read offline
33. 33.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Ocean"];
    show(songs[0]); (a) Ocean (b) Rain (c) Monsoon
34. 34.True or false: notes to read offline fits saving on the phone. (a) True (b) False
35. 35.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a shared to-do list (d) your last game level
36. 36.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Ocean"];
    show(songs[2]); (a) Rain (b) Monsoon (c) Ocean
37. 37.Which of these fits saving on the phone? (a) a draft you are typing (b) photos on two devices (c) a class leaderboard (d) chat messages to friends
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Sunrise (c) Stars
39. 39.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Arjun", "Kabir", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Arjun (c) Zoya (d) Kabir
40. 40.💾 What number does this code show?
    let stars = 3;
    stars = stars - 3;
    stars = stars + 3;
    show(stars);

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