App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 870 · 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 score = 4;
   score = score - 3;
   score = score + 5;
   show(score);
2. 2.True or false: your last game level fits saving on the phone. (a) False (b) True
3. 3.💾 What number does this code show?
   let stars = 8;
   stars = stars - 5;
   stars = stars + 2;
   show(stars);
4. 4.💾 What number does this code show?
   let score = 7;
   score = score - 3;
   score = score + 3;
   show(score);
5. 5.💾 What number does this code show?
   let stars = 8;
   stars = stars - 1;
   stars = stars + 1;
   show(stars);
6. 6.💾 What number does this code show?
   let songs = ["Kites", "Sunrise"];
   songs.push("Rain");
   show(songs.length);
7. 7.💾 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
8. 8.True or false: your last game level fits saving in the cloud. (a) True (b) False
9. 9.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) your last game level (d) a shared to-do list
10. 10.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
11. 11.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Stars", "Rain"];
    show(songs[2]); (a) Monsoon (b) Kites (c) Rain (d) Stars
12. 12.True or false: photos on two devices fits saving on the phone. (a) False (b) True
13. 13.💾 What number does this code show?
    let friends = ["Arjun", "Aman", "Zoya"];
    friends.push("Riya");
    show(friends.length);
14. 14.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
15. 15.💾 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
16. 16.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Rain", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Rain (c) Kites
17. 17.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Kabir", "Arjun"];
    show(friends[1]); (a) Riya (b) Arjun (c) Kabir
19. 19.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
20. 20.💾 What number does this code show?
    let friends = ["Arjun", "Meera", "Aman"];
    friends.push("Kabir");
    show(friends.length);
21. 21.💾 What number does this code show?
    let songs = ["Kites", "Sunrise"];
    songs.push("Monsoon");
    show(songs.length);
22. 22.Which of these fits saving in the cloud? (a) a draft you are typing (b) photos on two devices (c) the sound on/off setting (d) notes to read offline
23. 23.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
24. 24.Which of these fits saving in the cloud? (a) notes to read offline (b) a class leaderboard (c) the sound on/off setting (d) a draft you are typing
25. 25.💾 What number does this code show?
    let stars = 7;
    stars = stars - 3;
    stars = stars + 5;
    show(stars);
26. 26.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) chat messages to friends (d) a draft you are typing
27. 27.💾 What number does this code show?
    let score = 4;
    score = score - 1;
    score = score + 4;
    show(score);
28. 28.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Stars", "Sunrise", "Kites"];
    show(songs[3]); (a) Stars (b) Kites (c) Monsoon (d) Sunrise
29. 29.💾 What is a variable? (a) a named box for a value (b) a phone setting (c) a type of screen (d) a picture
30. 30.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
31. 31.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Kites", "Sunrise", "Monsoon", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Sunrise (c) Monsoon (d) Kites
32. 32.💾 What number does this code show?
    let score = 8;
    score = score - 7;
    score = score + 2;
    show(score);
33. 33.💾 Which can hold many values in order? (a) a list (b) a button (c) a single number (d) a switch
34. 34.💾 What number does this code show?
    let friends = ["Arjun", "Aman"];
    friends.push("Meera");
    friends.push("Riya");
    show(friends.length);
35. 35.💾 What number does this code show?
    let friends = ["Aman", "Kabir"];
    friends.push("Riya");
    show(friends.length);
36. 36.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
37. 37.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
38. 38.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
39. 39.💾 What number does this code show?
    let friends = ["Meera", "Arjun", "Zoya", "Aman"];
    friends.push("Riya");
    friends.push("Kabir");
    show(friends.length);
40. 40.Which of these fits saving on the phone? (a) chat messages to friends (b) notes to read offline (c) a class leaderboard (d) photos on two devices

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