App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 230 · 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 number does this code show?
   let friends = ["Zoya", "Riya"];
   friends.push("Meera");
   friends.push("Arjun");
   show(friends.length);
2. 2.Which of these fits saving in the cloud? (a) a shared to-do list (b) your last game level (c) notes to read offline (d) the sound on/off setting
3. 3.💾 What number does this code show?
   let friends = ["Aman", "Meera", "Arjun"];
   friends.push("Kabir");
   show(friends.length);
4. 4.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Monsoon", "Kites", "Stars", "Sunrise"];
   show(songs[4]); (a) Monsoon (b) Kites (c) Sunrise (d) Ocean
5. 5.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) a shared chat (d) data saved on the phone
6. 6.💾 What number does this code show?
   let notes = ["Hindi", "Music"];
   notes.push("Sports");
   show(notes.length);
7. 7.💾 What number does this code show?
   let friends = ["Zoya", "Arjun", "Kabir", "Aman"];
   friends.push("Meera");
   show(friends.length);
8. 8.Which of these fits saving on the phone? (a) photos on two devices (b) a draft you are typing (c) chat messages to friends (d) a shared to-do list
9. 9.💾 What does this code show? (Positions start at 0.)
   let friends = ["Riya", "Meera", "Zoya", "Kabir"];
   show(friends[2]); (a) Meera (b) Kabir (c) Zoya (d) Riya
10. 10.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a class leaderboard (d) notes to read offline
11. 11.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Music", "Art", "Sports", "Maths"];
    show(notes[0]); (a) Science (b) Music (c) Art (d) Sports
12. 12.💾 What number does this code show?
    let lives = 3;
    lives = lives - 3;
    lives = lives + 5;
    show(lives);
13. 13.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
14. 14.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Music", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Maths (c) Science
15. 15.💾 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
16. 16.Which of these fits saving on the phone? (a) your last game level (b) a class leaderboard (c) photos on two devices (d) chat messages to friends
17. 17.💾 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
18. 18.💾 What number does this code show?
    let songs = ["Ocean", "Kites", "Sunrise"];
    songs.push("Monsoon");
    show(songs.length);
19. 19.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the app is closed (c) the phone is lost (d) the screen turns off
20. 20.💾 What is a variable? (a) a picture (b) a type of screen (c) a named box for a value (d) a phone setting
21. 21.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
22. 22.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
23. 23.💾 What number does this code show?
    let score = 3;
    score = score - 3;
    score = score + 5;
    show(score);
24. 24.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) chat messages to friends (d) the sound on/off setting
25. 25.True or false: your last game level fits saving on the phone. (a) False (b) True
26. 26.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
27. 27.True or false: photos on two devices fits saving on the phone. (a) True (b) False
28. 28.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
30. 30.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
31. 31.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 0 (d) 1
32. 32.Which of these fits saving on the phone? (a) chat messages to friends (b) the sound on/off setting (c) photos on two devices (d) a shared to-do list
33. 33.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
34. 34.💾 What number does this code show?
    let points = 5;
    points = points - 4;
    points = points + 5;
    show(points);
35. 35.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Kabir", "Riya", "Zoya", "Meera"];
    show(friends[1]); (a) Riya (b) Aman (c) Kabir (d) Zoya
36. 36.💾 What number does this code show?
    let stars = 3;
    stars = stars - 1;
    stars = stars + 2;
    show(stars);
37. 37.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Monsoon", "Kites", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Stars (c) Kites (d) Rain
38. 38.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
39. 39.💾 What number does this code show?
    let songs = ["Kites", "Stars"];
    songs.push("Monsoon");
    songs.push("Rain");
    show(songs.length);
40. 40.💾 What number does this code show?
    let score = 8;
    score = score - 6;
    score = score + 5;
    show(score);

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