App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 963 · 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 points = 8;
   points = points - 8;
   points = points + 2;
   show(points);
2. 2.💾 What number does this code show?
   let songs = ["Sunrise", "Ocean", "Rain", "Stars"];
   songs.push("Monsoon");
   songs.push("Kites");
   show(songs.length);
3. 3.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) the sound on/off setting (d) a class leaderboard
4. 4.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 1 (c) 10 (d) 2
5. 5.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
6. 6.💾 What does this code show? (Positions start at 0.)
   let songs = ["Rain", "Stars", "Kites"];
   show(songs[0]); (a) Stars (b) Rain (c) Kites
7. 7.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Hindi", "Art", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Music (b) Sports (c) Hindi (d) Art
8. 8.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.💾 What number does this code show?
   let friends = ["Arjun", "Kabir"];
   friends.push("Aman");
   friends.push("Riya");
   show(friends.length);
10. 10.💾 What number does this code show?
    let friends = ["Riya", "Zoya", "Arjun"];
    friends.push("Aman");
    show(friends.length);
11. 11.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Rain", "Sunrise", "Kites"];
    show(songs[1]); (a) Kites (b) Stars (c) Rain (d) Sunrise
12. 12.💾 Which can hold many values in order? (a) a button (b) a list (c) a switch (d) a single number
13. 13.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
14. 14.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
15. 15.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the phone is lost (c) the app is closed (d) you send a message
16. 16.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
17. 17.💾 What number does this code show?
    let songs = ["Ocean", "Sunrise", "Monsoon"];
    songs.push("Rain");
    show(songs.length);
18. 18.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
19. 19.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a picture (d) a type of screen
20. 20.Which of these fits saving in the cloud? (a) chat messages to friends (b) notes to read offline (c) your last game level (d) the sound on/off setting
21. 21.💾 What number does this code show?
    let songs = ["Monsoon", "Sunrise", "Kites"];
    songs.push("Stars");
    show(songs.length);
22. 22.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) photos on two devices (d) notes to read offline
23. 23.True or false: photos on two devices fits saving on the phone. (a) False (b) True
24. 24.True or false: your last game level fits saving in the cloud. (a) False (b) True
25. 25.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a shared chat (c) a cloud backup (d) data saved on the phone
26. 26.💾 What number does this code show?
    let songs = ["Sunrise", "Kites"];
    songs.push("Rain");
    show(songs.length);
27. 27.True or false: your last game level fits saving on the phone. (a) True (b) False
28. 28.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
29. 29.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) never need a password (d) use it on any device
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Kites", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Stars (d) Kites
31. 31.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Riya", "Meera"];
    show(friends[1]); (a) Meera (b) Riya (c) Zoya
32. 32.💾 What number does this code show?
    let songs = ["Ocean", "Stars"];
    songs.push("Sunrise");
    show(songs.length);
33. 33.💾 What number does this code show?
    let friends = ["Meera", "Kabir"];
    friends.push("Arjun");
    show(friends.length);
34. 34.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Riya", "Meera", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Meera (c) Zoya (d) Arjun
35. 35.💾 What number does this code show?
    let stars = 5;
    stars = stars - 5;
    stars = stars + 1;
    show(stars);
36. 36.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Kites", "Monsoon", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Kites (c) Monsoon (d) Sunrise
37. 37.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
38. 38.💾 What number does this code show?
    let songs = ["Kites", "Sunrise"];
    songs.push("Monsoon");
    show(songs.length);
39. 39.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Kites", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Kites

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