App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 408 · 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.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
2. 2.💾 What number does this code show?
   let friends = ["Arjun", "Meera", "Aman"];
   friends.push("Zoya");
   friends.push("Kabir");
   show(friends.length);
3. 3.💾 What is a variable? (a) a type of screen (b) a phone setting (c) a picture (d) a named box for a value
4. 4.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
5. 5.💾 What does this code show? (Positions start at 0.)
   let notes = ["Science", "Music", "Hindi"];
   show(notes[2]); (a) Music (b) Science (c) Hindi
6. 6.💾 What does this code show? (Positions start at 0.)
   let friends = ["Zoya", "Aman", "Kabir"];
   show(friends[0]); (a) Aman (b) Zoya (c) Kabir
7. 7.True or false: your last game level fits saving on the phone. (a) True (b) False
8. 8.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Meera", "Zoya", "Riya", "Arjun"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Meera (b) Riya (c) Aman (d) Zoya
9. 9.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
10. 10.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a class leaderboard (d) a draft you are typing
11. 11.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) notes to read offline (d) a shared to-do list
12. 12.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Sports", "Music"];
    show(notes[0]); (a) Hindi (b) Sports (c) Music
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.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
15. 15.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Aman", "Arjun", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Aman (c) Kabir (d) Meera
16. 16.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Sports", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Sports (c) Science (d) Hindi
17. 17.💾 What number does this code show?
    let score = 4;
    score = score - 4;
    score = score + 5;
    show(score);
18. 18.💾 What number does this code show?
    let notes = ["Music", "Maths", "Science", "Art"];
    notes.push("Hindi");
    show(notes.length);
19. 19.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Hindi", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Science
20. 20.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
21. 21.💾 What number does this code show?
    let notes = ["Maths", "Sports"];
    notes.push("Hindi");
    show(notes.length);
22. 22.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) your last game level (d) chat messages to friends
23. 23.💾 What number does this code show?
    let points = 4;
    points = points - 4;
    points = points + 5;
    show(points);
24. 24.💾 What number does this code show?
    let friends = ["Riya", "Aman", "Meera", "Kabir"];
    friends.push("Arjun");
    friends.push("Zoya");
    show(friends.length);
25. 25.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) the phone is lost (d) you send a message
26. 26.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
27. 27.💾 Which works with no internet at all? (a) data saved on the phone (b) a shared chat (c) a cloud backup (d) a cloud leaderboard
28. 28.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
29. 29.True or false: photos on two devices fits saving on the phone. (a) True (b) False
30. 30.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) shrink the app (c) never need a password (d) skip the internet
31. 31.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
32. 32.💾 What number does this code show?
    let stars = 9;
    stars = stars - 6;
    stars = stars + 1;
    show(stars);
33. 33.Which of these fits saving in the cloud? (a) chat messages to friends (b) your last game level (c) the sound on/off setting (d) notes to read offline
34. 34.💾 What number does this code show?
    let songs = ["Rain", "Stars"];
    songs.push("Ocean");
    show(songs.length);
35. 35.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Aman", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Arjun (c) Meera
36. 36.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
37. 37.True or false: notes to read offline fits saving on the phone. (a) False (b) True
38. 38.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
39. 39.💾 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
40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Rain", "Monsoon", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Monsoon (c) Rain (d) Sunrise

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