App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 672 · 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 is a variable? (a) a named box for a value (b) a picture (c) a phone setting (d) a type of screen
2. 2.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) use it on any device (d) skip the internet
3. 3.💾 What number does this code show?
   let friends = ["Kabir", "Meera"];
   friends.push("Aman");
   show(friends.length);
4. 4.💾 What number does this code show?
   let songs = ["Sunrise", "Monsoon", "Rain", "Stars"];
   songs.push("Kites");
   songs.push("Ocean");
   show(songs.length);
5. 5.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
6. 6.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) your last game level (d) a shared to-do list
7. 7.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
8. 8.Which of these fits saving on the phone? (a) chat messages to friends (b) a draft you are typing (c) a class leaderboard (d) a shared to-do list
9. 9.💾 What number does this code show?
   let notes = ["Maths", "Art", "Hindi", "Music"];
   notes.push("Science");
   show(notes.length);
10. 10.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
11. 11.Which of these fits saving in the cloud? (a) a class leaderboard (b) your last game level (c) notes to read offline (d) a draft you are typing
12. 12.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) data saved on the phone (d) a shared chat
13. 13.💾 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
14. 14.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) photos on two devices
15. 15.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Sunrise", "Stars", "Ocean"];
    show(songs[0]); (a) Ocean (b) Monsoon (c) Sunrise (d) Stars
16. 16.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Sports", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Maths (c) Sports
17. 17.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the app is closed (d) the phone is lost
18. 18.Which of these fits saving on the phone? (a) chat messages to friends (b) a shared to-do list (c) notes to read offline (d) a class leaderboard
19. 19.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Aman", "Kabir", "Riya", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Arjun (d) Kabir
20. 20.💾 What number does this code show?
    let lives = 4;
    lives = lives - 1;
    lives = lives + 4;
    show(lives);
21. 21.💾 What number does this code show?
    let notes = ["Music", "Sports", "Hindi"];
    notes.push("Maths");
    notes.push("Science");
    show(notes.length);
22. 22.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Art", "Sports", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Art (c) Hindi (d) Sports
23. 23.Which of these fits saving in the cloud? (a) photos on two devices (b) the sound on/off setting (c) a draft you are typing (d) your last game level
24. 24.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) your last game level (d) a shared to-do list
25. 25.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
26. 26.💾 What number does this code show?
    let notes = ["Maths", "Hindi"];
    notes.push("Art");
    notes.push("Sports");
    show(notes.length);
27. 27.💾 What number does this code show?
    let notes = ["Maths", "Science", "Music", "Sports"];
    notes.push("Hindi");
    show(notes.length);
28. 28.💾 What number does this code show?
    let friends = ["Riya", "Meera", "Arjun"];
    friends.push("Aman");
    friends.push("Zoya");
    show(friends.length);
29. 29.💾 What number does this code show?
    let notes = ["Art", "Sports", "Music"];
    notes.push("Science");
    show(notes.length);
30. 30.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
31. 31.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
32. 32.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Ocean", "Kites", "Rain"];
    show(songs[0]); (a) Monsoon (b) Rain (c) Kites (d) Ocean
33. 33.💾 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
34. 34.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
35. 35.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Rain", "Ocean", "Kites"];
    show(songs[3]); (a) Sunrise (b) Rain (c) Ocean (d) Kites
36. 36.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
37. 37.💾 What number does this code show?
    let friends = ["Zoya", "Meera"];
    friends.push("Kabir");
    show(friends.length);
38. 38.💾 What number does this code show?
    let friends = ["Meera", "Arjun"];
    friends.push("Aman");
    show(friends.length);
39. 39.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 0 (d) 2
40. 40.💾 What number does this code show?
    let songs = ["Kites", "Rain"];
    songs.push("Stars");
    show(songs.length);

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