App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 333 · 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", "Art", "Music", "Hindi"];
   notes.push("Sports");
   show(notes.length);
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.💾 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
4. 4.💾 Which can hold many values in order? (a) a button (b) a list (c) a switch (d) a single number
5. 5.💾 pop() takes off the last item. What does this code show?
   let notes = ["Art", "Hindi", "Sports", "Science", "Music"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Hindi (b) Science (c) Sports (d) Art
6. 6.💾 pop() takes off the last item. What does this code show?
   let songs = ["Ocean", "Rain", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Kites
7. 7.💾 What number does this code show?
   let friends = ["Aman", "Meera", "Zoya", "Riya"];
   friends.push("Kabir");
   friends.push("Arjun");
   show(friends.length);
8. 8.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
10. 10.💾 What number does this code show?
    let notes = ["Art", "Sports", "Music", "Science"];
    notes.push("Maths");
    show(notes.length);
11. 11.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) photos on two devices (d) notes to read offline
12. 12.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) chat messages to friends (d) a shared to-do list
13. 13.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Stars", "Kites"];
    show(songs[0]); (a) Kites (b) Ocean (c) Stars
14. 14.💾 What number does this code show?
    let notes = ["Sports", "Art", "Maths", "Music"];
    notes.push("Hindi");
    show(notes.length);
15. 15.💾 What number does this code show?
    let coins = 4;
    coins = coins - 4;
    coins = coins + 5;
    show(coins);
16. 16.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) the phone is lost (d) you send a message
17. 17.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) a class leaderboard (d) notes to read offline
18. 18.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
19. 19.💾 What number does this code show?
    let points = 7;
    points = points - 1;
    points = points + 1;
    show(points);
20. 20.True or false: notes to read offline fits saving on the phone. (a) True (b) False
21. 21.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) chat messages to friends (d) your last game level
22. 22.Which of these fits saving in the cloud? (a) chat messages to friends (b) notes to read offline (c) the sound on/off setting (d) your last game level
23. 23.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Aman", "Meera", "Riya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Meera (c) Aman (d) Riya
24. 24.💾 What is a variable? (a) a type of screen (b) a phone setting (c) a picture (d) a named box for a value
25. 25.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
26. 26.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
27. 27.💾 What number does this code show?
    let lives = 3;
    lives = lives - 3;
    lives = lives + 3;
    show(lives);
28. 28.💾 What number does this code show?
    let friends = ["Zoya", "Riya"];
    friends.push("Aman");
    show(friends.length);
29. 29.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
30. 30.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
31. 31.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) shrink the app (c) never need a password (d) skip the internet
32. 32.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) photos on two devices (d) the sound on/off setting
33. 33.True or false: your last game level fits saving in the cloud. (a) False (b) True
34. 34.💾 What number does this code show?
    let lives = 6;
    lives = lives - 4;
    lives = lives + 2;
    show(lives);
35. 35.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
36. 36.💾 What number does this code show?
    let notes = ["Sports", "Art", "Music", "Science"];
    notes.push("Maths");
    show(notes.length);
37. 37.💾 What number does this code show?
    let lives = 3;
    lives = lives - 3;
    lives = lives + 4;
    show(lives);
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Stars", "Kites", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Monsoon (d) Stars
39. 39.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) chat messages to friends (d) a draft you are typing
40. 40.True or false: a class leaderboard fits saving on the phone. (a) True (b) False

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