App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 491 · 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.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
2. 2.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
3. 3.💾 What number does this code show?
   let songs = ["Stars", "Rain", "Ocean", "Sunrise"];
   songs.push("Kites");
   show(songs.length);
4. 4.💾 What number does this code show?
   let songs = ["Stars", "Sunrise"];
   songs.push("Ocean");
   show(songs.length);
5. 5.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Kites", "Rain"];
   show(songs[0]); (a) Kites (b) Rain (c) Ocean
6. 6.Which of these fits saving on the phone? (a) chat messages to friends (b) a shared to-do list (c) the sound on/off setting (d) a class leaderboard
7. 7.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
8. 8.💾 What number does this code show?
   let stars = 3;
   stars = stars - 1;
   stars = stars + 1;
   show(stars);
9. 9.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
10. 10.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) a draft you are typing (d) a class leaderboard
11. 11.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
12. 12.💾 What number does this code show?
    let score = 4;
    score = score - 2;
    score = score + 5;
    show(score);
13. 13.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
14. 14.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the screen turns off (c) the app is closed (d) the phone is lost
15. 15.💾 What number does this code show?
    let coins = 4;
    coins = coins - 2;
    coins = coins + 5;
    show(coins);
16. 16.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a draft you are typing (d) chat messages to friends
17. 17.💾 What number does this code show?
    let songs = ["Sunrise", "Kites", "Monsoon", "Stars"];
    songs.push("Ocean");
    songs.push("Rain");
    show(songs.length);
18. 18.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a draft you are typing (d) photos on two devices
19. 19.💾 What number does this code show?
    let songs = ["Kites", "Ocean", "Sunrise"];
    songs.push("Rain");
    songs.push("Stars");
    show(songs.length);
20. 20.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
21. 21.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Maths", "Art", "Music"];
    show(notes[1]); (a) Maths (b) Sports (c) Art (d) Music
22. 22.💾 What number does this code show?
    let songs = ["Rain", "Sunrise", "Kites", "Ocean"];
    songs.push("Monsoon");
    show(songs.length);
23. 23.💾 Which works with no internet at all? (a) a shared chat (b) data saved on the phone (c) a cloud backup (d) a cloud leaderboard
24. 24.💾 What number does this code show?
    let score = 3;
    score = score - 3;
    score = score + 4;
    show(score);
25. 25.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Kites", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Kites (c) Stars
26. 26.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Maths", "Music"];
    show(notes[1]); (a) Maths (b) Science (c) Music
27. 27.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Zoya", "Meera", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Riya (c) Meera (d) Zoya
28. 28.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
29. 29.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Zoya", "Kabir", "Arjun", "Meera"];
    show(friends[3]); (a) Kabir (b) Arjun (c) Riya (d) Zoya
30. 30.💾 What number does this code show?
    let friends = ["Aman", "Zoya", "Riya"];
    friends.push("Arjun");
    show(friends.length);
31. 31.💾 What number does this code show?
    let stars = 4;
    stars = stars - 4;
    stars = stars + 1;
    show(stars);
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) notes to read offline
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Science", "Maths", "Art"];
    show(notes[0]); (a) Art (b) Music (c) Science (d) Maths
34. 34.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Arjun", "Kabir"];
    show(friends[0]); (a) Arjun (b) Kabir (c) Meera
35. 35.💾 What is a variable? (a) a phone setting (b) a picture (c) a type of screen (d) a named box for a value
36. 36.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Rain", "Monsoon", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Kites (c) Rain (d) Ocean
37. 37.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
38. 38.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) skip the internet (d) use it on any device
39. 39.💾 What number does this code show?
    let friends = ["Aman", "Riya"];
    friends.push("Zoya");
    friends.push("Meera");
    show(friends.length);
40. 40.💾 What number does this code show?
    let coins = 6;
    coins = coins - 1;
    coins = coins + 5;
    show(coins);

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