App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 235 · 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 picture (c) a phone setting (d) a named box for a value
2. 2.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Riya", "Meera", "Arjun", "Zoya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Riya (b) Meera (c) Arjun (d) Aman
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Monsoon", "Rain", "Kites"];
   show(songs[3]); (a) Kites (b) Rain (c) Monsoon (d) Ocean
4. 4.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
5. 5.💾 What does this code show? (Positions start at 0.)
   let friends = ["Meera", "Arjun", "Zoya"];
   show(friends[1]); (a) Meera (b) Zoya (c) Arjun
6. 6.💾 Which works with no internet at all? (a) a shared chat (b) a cloud backup (c) a cloud leaderboard (d) data saved on the phone
7. 7.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Science", "Maths", "Art", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Science (b) Music (c) Maths (d) Art
8. 8.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Science", "Maths", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Science (b) Maths (c) Music (d) Sports
10. 10.💾 What number does this code show?
    let songs = ["Monsoon", "Kites", "Stars", "Sunrise"];
    songs.push("Rain");
    show(songs.length);
11. 11.💾 What number does this code show?
    let points = 4;
    points = points - 1;
    points = points + 1;
    show(points);
12. 12.True or false: notes to read offline fits saving on the phone. (a) False (b) True
13. 13.💾 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
14. 14.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Aman", "Riya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Arjun (c) Riya (d) Kabir
15. 15.True or false: your last game level fits saving in the cloud. (a) True (b) False
16. 16.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Ocean", "Kites"];
    show(songs[2]); (a) Kites (b) Rain (c) Monsoon (d) Ocean
17. 17.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
18. 18.💾 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
19. 19.Which of these fits saving on the phone? (a) chat messages to friends (b) the sound on/off setting (c) a class leaderboard (d) a shared to-do list
20. 20.💾 What number does this code show?
    let stars = 9;
    stars = stars - 5;
    stars = stars + 1;
    show(stars);
21. 21.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) your last game level (d) a shared to-do list
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.💾 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
24. 24.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) chat messages to friends (d) notes to read offline
25. 25.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
26. 26.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Sunrise", "Ocean", "Kites"];
    show(songs[0]); (a) Sunrise (b) Rain (c) Kites (d) Ocean
27. 27.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
28. 28.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Art", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Science
29. 29.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
30. 30.Which of these fits saving in the cloud? (a) photos on two devices (b) the sound on/off setting (c) notes to read offline (d) a draft you are typing
31. 31.💾 What number does this code show?
    let score = 7;
    score = score - 7;
    score = score + 5;
    show(score);
32. 32.💾 What number does this code show?
    let coins = 5;
    coins = coins - 4;
    coins = coins + 5;
    show(coins);
33. 33.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
34. 34.💾 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
35. 35.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) your last game level (d) chat messages to friends
36. 36.💾 What number does this code show?
    let coins = 3;
    coins = coins - 1;
    coins = coins + 2;
    show(coins);
37. 37.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
38. 38.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
39. 39.💾 What number does this code show?
    let score = 9;
    score = score - 5;
    score = score + 5;
    show(score);
40. 40.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Arjun", "Zoya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Meera (c) Arjun (d) Riya

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