App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 550 · 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.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
2. 2.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) the phone is lost (d) you send a message
3. 3.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.💾 What does this code show? (Positions start at 0.)
   let songs = ["Kites", "Ocean", "Sunrise"];
   show(songs[2]); (a) Kites (b) Ocean (c) Sunrise
5. 5.💾 What number does this code show?
   let stars = 8;
   stars = stars - 6;
   stars = stars + 2;
   show(stars);
6. 6.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.💾 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
8. 8.💾 What number does this code show?
   let stars = 9;
   stars = stars - 7;
   stars = stars + 3;
   show(stars);
9. 9.💾 What number does this code show?
   let notes = ["Music", "Hindi"];
   notes.push("Maths");
   notes.push("Science");
   show(notes.length);
10. 10.Which of these fits saving on the phone? (a) your last game level (b) photos on two devices (c) chat messages to friends (d) a class leaderboard
11. 11.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
12. 12.💾 What number does this code show?
    let stars = 5;
    stars = stars - 5;
    stars = stars + 2;
    show(stars);
13. 13.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) use it on any device (d) skip the internet
14. 14.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a draft you are typing (d) chat messages to friends
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Sports", "Science", "Hindi", "Art"];
    show(notes[0]); (a) Hindi (b) Sports (c) Music (d) Science
16. 16.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
17. 17.💾 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
18. 18.💾 What number does this code show?
    let notes = ["Hindi", "Music"];
    notes.push("Sports");
    show(notes.length);
19. 19.Which of these fits saving on the phone? (a) photos on two devices (b) the sound on/off setting (c) a shared to-do list (d) a class leaderboard
20. 20.💾 What number does this code show?
    let stars = 9;
    stars = stars - 1;
    stars = stars + 1;
    show(stars);
21. 21.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
22. 22.💾 Which can hold many values in order? (a) a button (b) a single number (c) a list (d) a switch
23. 23.💾 What number does this code show?
    let friends = ["Riya", "Arjun", "Aman", "Zoya"];
    friends.push("Meera");
    show(friends.length);
24. 24.Which of these fits saving in the cloud? (a) your last game level (b) photos on two devices (c) notes to read offline (d) the sound on/off setting
25. 25.True or false: photos on two devices fits saving on the phone. (a) True (b) False
26. 26.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Stars", "Sunrise", "Rain", "Kites"];
    show(songs[2]); (a) Rain (b) Ocean (c) Stars (d) Sunrise
27. 27.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Science", "Maths"];
    show(notes[0]); (a) Hindi (b) Science (c) Maths
28. 28.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Meera", "Arjun"];
    show(friends[2]); (a) Riya (b) Arjun (c) Meera
29. 29.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
30. 30.Which of these fits saving on the phone? (a) a shared to-do list (b) notes to read offline (c) photos on two devices (d) chat messages to friends
31. 31.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 2 (c) 0 (d) 1
32. 32.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
33. 33.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Aman", "Meera", "Arjun", "Riya"];
    show(friends[3]); (a) Aman (b) Meera (c) Arjun (d) Kabir
34. 34.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Hindi", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Science
35. 35.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Sports", "Art", "Science", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Sports (c) Music (d) Science
36. 36.Which of these fits saving in the cloud? (a) a draft you are typing (b) a class leaderboard (c) your last game level (d) notes to read offline
37. 37.💾 What number does this code show?
    let score = 8;
    score = score - 5;
    score = score + 4;
    show(score);
38. 38.💾 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
39. 39.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
40. 40.💾 What number does this code show?
    let score = 8;
    score = score - 7;
    score = score + 4;
    show(score);

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