App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 260 · 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 photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
2. 2.💾 What number does this code show?
   let songs = ["Sunrise", "Kites"];
   songs.push("Ocean");
   show(songs.length);
3. 3.💾 What number does this code show?
   let points = 7;
   points = points - 4;
   points = points + 2;
   show(points);
4. 4.💾 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
5. 5.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.💾 What number does this code show?
   let notes = ["Maths", "Art", "Hindi", "Music"];
   notes.push("Science");
   show(notes.length);
7. 7.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) the sound on/off setting (d) a class leaderboard
8. 8.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
9. 9.💾 What number does this code show?
   let songs = ["Stars", "Ocean", "Rain"];
   songs.push("Sunrise");
   songs.push("Monsoon");
   show(songs.length);
10. 10.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
11. 11.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Stars", "Rain", "Sunrise"];
    show(songs[3]); (a) Sunrise (b) Rain (c) Kites (d) Stars
12. 12.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
13. 13.💾 What number does this code show?
    let friends = ["Riya", "Arjun", "Kabir", "Meera"];
    friends.push("Aman");
    show(friends.length);
14. 14.💾 What number does this code show?
    let notes = ["Sports", "Maths", "Music"];
    notes.push("Science");
    notes.push("Art");
    show(notes.length);
15. 15.💾 What number does this code show?
    let friends = ["Zoya", "Aman"];
    friends.push("Riya");
    friends.push("Meera");
    show(friends.length);
16. 16.True or false: photos on two devices fits saving on the phone. (a) False (b) True
17. 17.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) notes to read offline
18. 18.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Monsoon", "Kites", "Sunrise"];
    show(songs[3]); (a) Kites (b) Sunrise (c) Rain (d) Monsoon
19. 19.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Art", "Hindi"];
    show(notes[2]); (a) Music (b) Maths (c) Art (d) Hindi
20. 20.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
21. 21.True or false: your last game level fits saving on the phone. (a) False (b) True
22. 22.💾 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
23. 23.💾 What number does this code show?
    let friends = ["Zoya", "Arjun", "Kabir"];
    friends.push("Riya");
    friends.push("Aman");
    show(friends.length);
24. 24.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a shared chat (c) data saved on the phone (d) a cloud backup
25. 25.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
26. 26.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Science", "Music", "Maths", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Maths (c) Hindi (d) Science
27. 27.💾 What number does this code show?
    let stars = 6;
    stars = stars - 2;
    stars = stars + 5;
    show(stars);
28. 28.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Aman", "Kabir"];
    show(friends[2]); (a) Riya (b) Kabir (c) Aman
29. 29.💾 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
30. 30.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
31. 31.💾 What number does this code show?
    let stars = 3;
    stars = stars - 1;
    stars = stars + 4;
    show(stars);
32. 32.Which of these fits saving in the cloud? (a) a draft you are typing (b) chat messages to friends (c) your last game level (d) the sound on/off setting
33. 33.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
34. 34.Which of these fits saving in the cloud? (a) photos on two devices (b) your last game level (c) notes to read offline (d) the sound on/off setting
35. 35.💾 What number does this code show?
    let songs = ["Kites", "Stars", "Monsoon"];
    songs.push("Ocean");
    show(songs.length);
36. 36.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Science", "Hindi"];
    show(notes[1]); (a) Hindi (b) Art (c) Maths (d) Science
37. 37.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Rain", "Kites"];
    show(songs[0]); (a) Sunrise (b) Rain (c) Kites
38. 38.Which of these fits saving on the phone? (a) chat messages to friends (b) a draft you are typing (c) a shared to-do list (d) photos on two devices
39. 39.💾 What number does this code show?
    let lives = 5;
    lives = lives - 5;
    lives = lives + 1;
    show(lives);
40. 40.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Hindi", "Music", "Maths", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Hindi (c) Art (d) Music

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