App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 865 · 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.💾 Which works with no internet at all? (a) data saved on the phone (b) a shared chat (c) a cloud leaderboard (d) a cloud backup
2. 2.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) you send a message (c) the screen turns off (d) the app is closed
3. 3.💾 pop() takes off the last item. What does this code show?
   let friends = ["Riya", "Kabir", "Arjun", "Zoya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Kabir (b) Riya (c) Zoya (d) Arjun
4. 4.💾 What does this code show? (Positions start at 0.)
   let songs = ["Monsoon", "Rain", "Kites"];
   show(songs[0]); (a) Rain (b) Kites (c) Monsoon
5. 5.💾 What does this code show? (Positions start at 0.)
   let friends = ["Aman", "Riya", "Arjun"];
   show(friends[2]); (a) Aman (b) Arjun (c) Riya
6. 6.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.True or false: your last game level fits saving in the cloud. (a) True (b) False
8. 8.💾 What is a variable? (a) a picture (b) a named box for a value (c) a type of screen (d) a phone setting
9. 9.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
10. 10.💾 What number does this code show?
    let notes = ["Art", "Science", "Maths"];
    notes.push("Music");
    show(notes.length);
11. 11.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Sunrise", "Ocean", "Kites", "Monsoon"];
    show(songs[1]); (a) Stars (b) Kites (c) Ocean (d) Sunrise
12. 12.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Arjun", "Riya", "Kabir", "Meera"];
    show(friends[1]); (a) Aman (b) Kabir (c) Riya (d) Arjun
13. 13.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
14. 14.💾 What number does this code show?
    let notes = ["Music", "Maths", "Science", "Art"];
    notes.push("Hindi");
    notes.push("Sports");
    show(notes.length);
15. 15.💾 What number does this code show?
    let friends = ["Aman", "Meera", "Zoya"];
    friends.push("Kabir");
    friends.push("Riya");
    show(friends.length);
16. 16.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) in the cloud (b) on the phone
17. 17.💾 What number does this code show?
    let friends = ["Zoya", "Aman", "Arjun", "Meera"];
    friends.push("Kabir");
    friends.push("Riya");
    show(friends.length);
18. 18.💾 What number does this code show?
    let songs = ["Kites", "Monsoon"];
    songs.push("Stars");
    show(songs.length);
19. 19.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Kabir"];
    show(friends[2]); (a) Kabir (b) Arjun (c) Riya
20. 20.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Sunrise", "Rain", "Stars"];
    show(songs[0]); (a) Rain (b) Ocean (c) Sunrise (d) Stars
21. 21.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
22. 22.Which of these fits saving in the cloud? (a) notes to read offline (b) chat messages to friends (c) the sound on/off setting (d) your last game level
23. 23.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Monsoon", "Stars"];
    show(songs[0]); (a) Stars (b) Sunrise (c) Monsoon
24. 24.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 0 (d) 10
25. 25.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
26. 26.💾 What number does this code show?
    let friends = ["Zoya", "Riya"];
    friends.push("Aman");
    show(friends.length);
27. 27.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a shared to-do list (d) your last game level
28. 28.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Zoya", "Riya", "Meera", "Arjun"];
    show(friends[1]); (a) Kabir (b) Riya (c) Zoya (d) Meera
29. 29.True or false: your last game level fits saving on the phone. (a) False (b) True
30. 30.💾 What number does this code show?
    let lives = 6;
    lives = lives - 1;
    lives = lives + 5;
    show(lives);
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Kites", "Ocean", "Rain"];
    show(songs[3]); (a) Sunrise (b) Rain (c) Kites (d) Ocean
32. 32.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Rain", "Stars", "Sunrise"];
    show(songs[2]); (a) Stars (b) Rain (c) Kites (d) Sunrise
33. 33.💾 What number does this code show?
    let lives = 8;
    lives = lives - 3;
    lives = lives + 1;
    show(lives);
34. 34.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
35. 35.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) never need a password (d) use it on any device
36. 36.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Riya", "Kabir"];
    show(friends[1]); (a) Kabir (b) Riya (c) Zoya
37. 37.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) your last game level (d) a class leaderboard
38. 38.💾 What number does this code show?
    let friends = ["Aman", "Riya", "Zoya"];
    friends.push("Kabir");
    show(friends.length);
39. 39.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Sports", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Sports (c) Maths
40. 40.True or false: a draft you are typing fits saving on the phone. (a) True (b) False

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