App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 629 · 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 on the phone? (a) a class leaderboard (b) your last game level (c) photos on two devices (d) chat messages to friends
2. 2.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
3. 3.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the phone is lost (d) the screen turns off
4. 4.💾 What does this code show? (Positions start at 0.)
   let friends = ["Arjun", "Aman", "Zoya", "Riya", "Meera"];
   show(friends[3]); (a) Arjun (b) Zoya (c) Riya (d) Aman
5. 5.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
6. 6.True or false: your last game level fits saving in the cloud. (a) True (b) False
7. 7.💾 pop() takes off the last item. What does this code show?
   let songs = ["Sunrise", "Monsoon", "Kites", "Rain"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Monsoon (b) Sunrise (c) Rain (d) Kites
8. 8.True or false: notes to read offline fits saving on the phone. (a) False (b) True
9. 9.💾 What number does this code show?
   let friends = ["Riya", "Zoya", "Meera", "Arjun"];
   friends.push("Aman");
   friends.push("Kabir");
   show(friends.length);
10. 10.Which of these fits saving on the phone? (a) a draft you are typing (b) a shared to-do list (c) chat messages to friends (d) a class leaderboard
11. 11.💾 What number does this code show?
    let stars = 7;
    stars = stars - 3;
    stars = stars + 2;
    show(stars);
12. 12.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
13. 13.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
14. 14.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) on the phone (b) in the cloud
15. 15.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
16. 16.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
17. 17.💾 What number does this code show?
    let notes = ["Art", "Science", "Maths"];
    notes.push("Hindi");
    notes.push("Music");
    show(notes.length);
18. 18.💾 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
19. 19.Which of these fits saving in the cloud? (a) notes to read offline (b) a shared to-do list (c) a draft you are typing (d) the sound on/off setting
20. 20.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Zoya", "Kabir", "Meera", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Meera (c) Zoya (d) Kabir
21. 21.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a list (d) a button
22. 22.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Zoya", "Kabir", "Riya", "Meera"];
    show(friends[0]); (a) Zoya (b) Riya (c) Arjun (d) Kabir
23. 23.💾 What number does this code show?
    let points = 9;
    points = points - 1;
    points = points + 5;
    show(points);
24. 24.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
25. 25.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
26. 26.💾 What number does this code show?
    let points = 7;
    points = points - 4;
    points = points + 2;
    show(points);
27. 27.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
28. 28.💾 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
29. 29.Which of these fits saving in the cloud? (a) chat messages to friends (b) the sound on/off setting (c) a draft you are typing (d) notes to read offline
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Maths", "Art", "Music"];
    show(notes[2]); (a) Maths (b) Hindi (c) Music (d) Art
31. 31.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) photos on two devices (d) the sound on/off setting
32. 32.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
33. 33.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) use it on any device (c) never need a password (d) skip the internet
34. 34.💾 What number does this code show?
    let friends = ["Kabir", "Aman", "Meera"];
    friends.push("Arjun");
    friends.push("Riya");
    show(friends.length);
35. 35.💾 What number does this code show?
    let friends = ["Zoya", "Aman", "Kabir", "Meera"];
    friends.push("Arjun");
    show(friends.length);
36. 36.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Music", "Hindi"];
    show(notes[2]); (a) Music (b) Art (c) Hindi (d) Maths
37. 37.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
38. 38.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Ocean"];
    show(songs[2]); (a) Sunrise (b) Kites (c) Ocean
39. 39.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
40. 40.💾 What number does this code show?
    let notes = ["Maths", "Art"];
    notes.push("Hindi");
    show(notes.length);

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