App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 242 · 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 works with no internet at all? (a) data saved on the phone (b) a shared chat (c) a cloud leaderboard (d) a cloud backup
2. 2.💾 What number does this code show?
   let coins = 4;
   coins = coins - 2;
   coins = coins + 1;
   show(coins);
3. 3.💾 What number does this code show?
   let stars = 5;
   stars = stars - 3;
   stars = stars + 5;
   show(stars);
4. 4.💾 What number does this code show?
   let notes = ["Sports", "Hindi", "Art", "Maths"];
   notes.push("Music");
   notes.push("Science");
   show(notes.length);
5. 5.💾 pop() takes off the last item. What does this code show?
   let songs = ["Sunrise", "Monsoon", "Rain", "Stars", "Ocean"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Rain (b) Stars (c) Sunrise (d) Monsoon
6. 6.💾 pop() takes off the last item. What does this code show?
   let friends = ["Kabir", "Riya", "Arjun", "Zoya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Kabir (b) Riya (c) Arjun (d) Zoya
7. 7.Which of these fits saving on the phone? (a) chat messages to friends (b) the sound on/off setting (c) a class leaderboard (d) a shared to-do list
8. 8.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
9. 9.💾 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
10. 10.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Sports", "Art", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Music (d) Art
11. 11.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
12. 12.Which of these fits saving on the phone? (a) your last game level (b) a shared to-do list (c) a class leaderboard (d) chat messages to friends
13. 13.💾 What is a variable? (a) a picture (b) a phone setting (c) a named box for a value (d) a type of screen
14. 14.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Music", "Hindi", "Science"];
    show(notes[1]); (a) Art (b) Maths (c) Hindi (d) Music
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.Which of these fits saving in the cloud? (a) a draft you are typing (b) a shared to-do list (c) the sound on/off setting (d) notes to read offline
18. 18.True or false: notes to read offline fits saving on the phone. (a) True (b) False
19. 19.Which of these fits saving on the phone? (a) chat messages to friends (b) a draft you are typing (c) photos on two devices (d) a class leaderboard
20. 20.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Aman", "Riya", "Arjun", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Riya (c) Aman (d) Meera
21. 21.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 10 (c) 2 (d) 1
22. 22.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
23. 23.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Science", "Sports", "Hindi", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Science (c) Music (d) Sports
24. 24.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Music", "Science", "Hindi", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Hindi (c) Science (d) Music
25. 25.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) notes to read offline (d) photos on two devices
26. 26.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
27. 27.💾 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
28. 28.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Science", "Music", "Art"];
    show(notes[1]); (a) Music (b) Science (c) Hindi (d) Art
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Stars", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Monsoon (c) Stars
31. 31.💾 What number does this code show?
    let songs = ["Rain", "Sunrise"];
    songs.push("Ocean");
    show(songs.length);
32. 32.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
33. 33.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
34. 34.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
35. 35.💾 What number does this code show?
    let notes = ["Music", "Science"];
    notes.push("Hindi");
    show(notes.length);
36. 36.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
37. 37.💾 What number does this code show?
    let lives = 9;
    lives = lives - 3;
    lives = lives + 1;
    show(lives);
38. 38.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) a class leaderboard (d) a draft you are typing
39. 39.💾 Saving data in the cloud lets you ___. (a) never need a password (b) skip the internet (c) shrink the app (d) use it on any device
40. 40.💾 What number does this code show?
    let songs = ["Sunrise", "Monsoon"];
    songs.push("Rain");
    songs.push("Stars");
    show(songs.length);

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