App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 766 · 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 does this code show? (Positions start at 0.)
   let friends = ["Zoya", "Arjun", "Meera", "Riya", "Aman"];
   show(friends[0]); (a) Arjun (b) Riya (c) Zoya (d) Meera
2. 2.💾 What number does this code show?
   let notes = ["Music", "Science", "Maths"];
   notes.push("Hindi");
   show(notes.length);
3. 3.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
4. 4.Which of these fits saving on the phone? (a) a class leaderboard (b) your last game level (c) chat messages to friends (d) a shared to-do list
5. 5.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.Which of these fits saving in the cloud? (a) photos on two devices (b) notes to read offline (c) a draft you are typing (d) the sound on/off setting
7. 7.💾 pop() takes off the last item. What does this code show?
   let friends = ["Riya", "Arjun", "Kabir", "Zoya", "Meera"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Riya (b) Zoya (c) Arjun (d) Kabir
8. 8.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
9. 9.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) data saved on the phone (d) a shared chat
10. 10.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Hindi", "Science", "Maths"];
    show(notes[1]); (a) Maths (b) Hindi (c) Science (d) Music
11. 11.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Zoya", "Meera", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Riya (d) Zoya
12. 12.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Science", "Music", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Maths (c) Music (d) Science
13. 13.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Hindi", "Art"];
    show(notes[0]); (a) Hindi (b) Art (c) Music
14. 14.💾 What number does this code show?
    let friends = ["Riya", "Arjun", "Zoya"];
    friends.push("Meera");
    show(friends.length);
15. 15.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Music", "Science", "Art", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Music (c) Science (d) Art
16. 16.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) your last game level (d) chat messages to friends
17. 17.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
18. 18.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) use it on any device (d) skip the internet
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 = ["Meera", "Zoya"];
    friends.push("Aman");
    friends.push("Kabir");
    show(friends.length);
21. 21.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
22. 22.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Sunrise", "Monsoon", "Kites"];
    show(songs[2]); (a) Sunrise (b) Monsoon (c) Kites (d) Rain
23. 23.💾 What number does this code show?
    let songs = ["Ocean", "Monsoon", "Rain"];
    songs.push("Stars");
    songs.push("Kites");
    show(songs.length);
24. 24.💾 What number does this code show?
    let songs = ["Ocean", "Kites"];
    songs.push("Monsoon");
    show(songs.length);
25. 25.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) a class leaderboard (d) notes to read offline
26. 26.💾 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
27. 27.💾 What number does this code show?
    let friends = ["Zoya", "Meera"];
    friends.push("Riya");
    friends.push("Arjun");
    show(friends.length);
28. 28.💾 What number does this code show?
    let friends = ["Aman", "Meera", "Riya"];
    friends.push("Kabir");
    show(friends.length);
29. 29.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
30. 30.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
31. 31.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
32. 32.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
33. 33.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) chat messages to friends (d) the sound on/off setting
34. 34.💾 What number does this code show?
    let songs = ["Rain", "Monsoon", "Ocean"];
    songs.push("Sunrise");
    songs.push("Stars");
    show(songs.length);
35. 35.True or false: your last game level fits saving in the cloud. (a) False (b) True
36. 36.💾 What is a variable? (a) a named box for a value (b) a picture (c) a type of screen (d) a phone setting
37. 37.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Kites", "Stars", "Sunrise", "Monsoon"];
    show(songs[2]); (a) Ocean (b) Kites (c) Sunrise (d) Stars
38. 38.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Stars", "Rain"];
    show(songs[1]); (a) Sunrise (b) Stars (c) Rain
39. 39.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Riya", "Kabir", "Zoya", "Arjun"];
    show(friends[1]); (a) Zoya (b) Kabir (c) Riya (d) Meera
40. 40.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the screen turns off (c) the phone is lost (d) the app is closed

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