App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 302 · 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 songs = ["Kites", "Monsoon"];
   songs.push("Stars");
   songs.push("Sunrise");
   show(songs.length);
2. 2.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) your last game level (d) a shared to-do list
3. 3.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) a draft you are typing (d) chat messages to friends
4. 4.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
5. 5.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 10 (c) 1 (d) 2
6. 6.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
7. 7.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
8. 8.💾 What number does this code show?
   let stars = 7;
   stars = stars - 4;
   stars = stars + 2;
   show(stars);
9. 9.💾 What does this code show? (Positions start at 0.)
   let notes = ["Science", "Hindi", "Music"];
   show(notes[0]); (a) Music (b) Hindi (c) Science
10. 10.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
11. 11.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
12. 12.True or false: notes to read offline fits saving on the phone. (a) False (b) True
13. 13.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
14. 14.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a list (d) a button
15. 15.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Kabir", "Arjun", "Zoya", "Aman"];
    show(friends[2]); (a) Kabir (b) Zoya (c) Meera (d) Arjun
16. 16.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
17. 17.💾 What number does this code show?
    let score = 6;
    score = score - 3;
    score = score + 4;
    show(score);
18. 18.💾 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
19. 19.💾 What number does this code show?
    let friends = ["Aman", "Arjun", "Zoya", "Meera"];
    friends.push("Kabir");
    show(friends.length);
20. 20.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Rain", "Ocean", "Sunrise", "Monsoon"];
    show(songs[4]); (a) Rain (b) Ocean (c) Stars (d) Monsoon
21. 21.💾 What number does this code show?
    let lives = 4;
    lives = lives - 4;
    lives = lives + 5;
    show(lives);
22. 22.True or false: your last game level fits saving in the cloud. (a) True (b) False
23. 23.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) photos on two devices (d) a draft you are typing
24. 24.💾 What number does this code show?
    let songs = ["Sunrise", "Rain"];
    songs.push("Ocean");
    songs.push("Stars");
    show(songs.length);
25. 25.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) on the phone (b) in the cloud
26. 26.💾 What number does this code show?
    let score = 5;
    score = score - 4;
    score = score + 5;
    show(score);
27. 27.💾 What is a variable? (a) a phone setting (b) a picture (c) a named box for a value (d) a type of screen
28. 28.💾 What number does this code show?
    let points = 4;
    points = points - 4;
    points = points + 3;
    show(points);
29. 29.💾 Which works with no internet at all? (a) a cloud backup (b) a shared chat (c) data saved on the phone (d) a cloud leaderboard
30. 30.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) photos on two devices (d) the sound on/off setting
31. 31.Which of these fits saving in the cloud? (a) a class leaderboard (b) a draft you are typing (c) the sound on/off setting (d) your last game level
32. 32.💾 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
33. 33.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Meera", "Riya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Riya (c) Arjun (d) Meera
34. 34.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the app is closed (c) the phone is lost (d) you send a message
35. 35.Which of these fits saving on the phone? (a) the sound on/off setting (b) a class leaderboard (c) chat messages to friends (d) photos on two devices
36. 36.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Arjun", "Riya", "Zoya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Arjun (c) Zoya (d) Meera
37. 37.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
38. 38.💾 What number does this code show?
    let lives = 3;
    lives = lives - 2;
    lives = lives + 5;
    show(lives);
39. 39.💾 What number does this code show?
    let score = 9;
    score = score - 5;
    score = score + 3;
    show(score);
40. 40.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Science", "Sports", "Music"];
    show(notes[2]); (a) Art (b) Science (c) Music (d) Sports

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