App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 135 · 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 in the cloud? (a) your last game level (b) notes to read offline (c) a draft you are typing (d) chat messages to friends
2. 2.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
3. 3.💾 What number does this code show?
   let friends = ["Aman", "Kabir", "Riya"];
   friends.push("Arjun");
   show(friends.length);
4. 4.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
5. 5.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
6. 6.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the phone is lost (c) you send a message (d) the app is closed
7. 7.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
8. 8.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) notes to read offline (d) photos on two devices
9. 9.💾 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
10. 10.💾 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
11. 11.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Arjun", "Aman", "Kabir", "Meera"];
    show(friends[1]); (a) Aman (b) Zoya (c) Kabir (d) Arjun
12. 12.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
13. 13.💾 What number does this code show?
    let notes = ["Sports", "Art", "Music"];
    notes.push("Maths");
    show(notes.length);
14. 14.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) a draft you are typing (d) a shared to-do list
15. 15.Which of these fits saving on the phone? (a) your last game level (b) a shared to-do list (c) chat messages to friends (d) photos on two devices
16. 16.💾 What number does this code show?
    let notes = ["Music", "Art", "Science"];
    notes.push("Sports");
    show(notes.length);
17. 17.💾 What number does this code show?
    let lives = 6;
    lives = lives - 2;
    lives = lives + 5;
    show(lives);
18. 18.True or false: photos on two devices fits saving on the phone. (a) True (b) False
19. 19.💾 What number does this code show?
    let score = 8;
    score = score - 8;
    score = score + 4;
    show(score);
20. 20.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Meera", "Kabir", "Zoya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Aman (d) Meera
21. 21.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a shared to-do list (c) a draft you are typing (d) your last game level
22. 22.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 1 (d) 2
23. 23.💾 What number does this code show?
    let songs = ["Monsoon", "Rain", "Stars", "Ocean"];
    songs.push("Kites");
    songs.push("Sunrise");
    show(songs.length);
24. 24.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
25. 25.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) skip the internet (c) never need a password (d) shrink the app
26. 26.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
27. 27.💾 Which can hold many values in order? (a) a switch (b) a button (c) a single number (d) a list
28. 28.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.💾 What number does this code show?
    let points = 9;
    points = points - 2;
    points = points + 1;
    show(points);
30. 30.💾 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
31. 31.True or false: notes to read offline fits saving on the phone. (a) True (b) False
32. 32.💾 What number does this code show?
    let coins = 5;
    coins = coins - 1;
    coins = coins + 2;
    show(coins);
33. 33.💾 What number does this code show?
    let friends = ["Kabir", "Arjun"];
    friends.push("Aman");
    show(friends.length);
34. 34.💾 What number does this code show?
    let friends = ["Arjun", "Riya", "Aman"];
    friends.push("Kabir");
    friends.push("Meera");
    show(friends.length);
35. 35.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Meera", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Riya (c) Aman
36. 36.💾 What number does this code show?
    let coins = 7;
    coins = coins - 4;
    coins = coins + 3;
    show(coins);
37. 37.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Monsoon", "Kites"];
    show(songs[2]); (a) Kites (b) Sunrise (c) Monsoon
38. 38.💾 What number does this code show?
    let score = 3;
    score = score - 3;
    score = score + 2;
    show(score);
39. 39.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) notes to read offline (d) a class leaderboard
40. 40.💾 What number does this code show?
    let lives = 5;
    lives = lives - 3;
    lives = lives + 4;
    show(lives);

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