App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 613 · 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 type of screen (b) a named box for a value (c) a picture (d) a phone setting
2. 2.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) shrink the app (d) never need a password
3. 3.True or false: notes to read offline fits saving on the phone. (a) False (b) True
4. 4.💾 pop() takes off the last item. What does this code show?
   let friends = ["Riya", "Meera", "Aman", "Kabir"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Riya (b) Kabir (c) Meera (d) Aman
5. 5.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud backup (c) a shared chat (d) a cloud leaderboard
6. 6.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 0 (d) 2
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.💾 What number does this code show?
   let friends = ["Aman", "Riya", "Zoya", "Arjun"];
   friends.push("Kabir");
   show(friends.length);
9. 9.💾 What number does this code show?
   let songs = ["Kites", "Monsoon", "Stars", "Rain"];
   songs.push("Sunrise");
   songs.push("Ocean");
   show(songs.length);
10. 10.💾 What number does this code show?
    let songs = ["Rain", "Monsoon"];
    songs.push("Kites");
    songs.push("Sunrise");
    show(songs.length);
11. 11.True or false: your last game level fits saving in the cloud. (a) True (b) False
12. 12.💾 What number does this code show?
    let friends = ["Riya", "Meera", "Aman"];
    friends.push("Kabir");
    friends.push("Zoya");
    show(friends.length);
13. 13.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) photos on two devices (d) a shared to-do list
14. 14.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
15. 15.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) photos on two devices (d) the sound on/off setting
16. 16.💾 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
17. 17.💾 What number does this code show?
    let songs = ["Rain", "Sunrise"];
    songs.push("Monsoon");
    show(songs.length);
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Aman", "Zoya", "Kabir"];
    show(friends[3]); (a) Zoya (b) Aman (c) Riya (d) Arjun
19. 19.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
20. 20.💾 What number does this code show?
    let stars = 6;
    stars = stars - 3;
    stars = stars + 5;
    show(stars);
21. 21.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
22. 22.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
23. 23.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
24. 24.💾 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
25. 25.💾 What number does this code show?
    let points = 8;
    points = points - 2;
    points = points + 2;
    show(points);
26. 26.💾 What number does this code show?
    let stars = 6;
    stars = stars - 5;
    stars = stars + 1;
    show(stars);
27. 27.💾 Which can hold many values in order? (a) a single number (b) a list (c) a button (d) a switch
28. 28.💾 What number does this code show?
    let friends = ["Meera", "Arjun"];
    friends.push("Zoya");
    friends.push("Riya");
    show(friends.length);
29. 29.💾 What number does this code show?
    let points = 9;
    points = points - 6;
    points = points + 4;
    show(points);
30. 30.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
31. 31.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Kabir (c) Zoya
32. 32.💾 What number does this code show?
    let points = 4;
    points = points - 1;
    points = points + 1;
    show(points);
33. 33.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) a draft you are typing (d) chat messages to friends
34. 34.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Riya", "Aman", "Meera", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Zoya (c) Riya (d) Meera
35. 35.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) photos on two devices (d) the sound on/off setting
36. 36.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
37. 37.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Zoya", "Meera"];
    show(friends[0]); (a) Aman (b) Meera (c) Zoya
38. 38.💾 What number does this code show?
    let score = 7;
    score = score - 3;
    score = score + 4;
    show(score);
39. 39.💾 What number does this code show?
    let songs = ["Ocean", "Rain", "Stars", "Sunrise"];
    songs.push("Monsoon");
    songs.push("Kites");
    show(songs.length);
40. 40.💾 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

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