App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 605 · 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.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
2. 2.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
3. 3.💾 pop() takes off the last item. What does this code show?
   let songs = ["Sunrise", "Stars", "Kites", "Monsoon"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Monsoon (b) Stars (c) Sunrise (d) Kites
4. 4.💾 What does this code show? (Positions start at 0.)
   let songs = ["Stars", "Kites", "Sunrise"];
   show(songs[2]); (a) Stars (b) Sunrise (c) Kites
5. 5.💾 What number does this code show?
   let songs = ["Rain", "Stars", "Ocean", "Monsoon"];
   songs.push("Kites");
   songs.push("Sunrise");
   show(songs.length);
6. 6.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
7. 7.💾 What number does this code show?
   let coins = 8;
   coins = coins - 7;
   coins = coins + 4;
   show(coins);
8. 8.💾 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
9. 9.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
10. 10.💾 Which works with no internet at all? (a) a shared chat (b) a cloud leaderboard (c) a cloud backup (d) data saved on the phone
11. 11.💾 What number does this code show?
    let coins = 7;
    coins = coins - 7;
    coins = coins + 3;
    show(coins);
12. 12.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
13. 13.💾 What number does this code show?
    let notes = ["Music", "Hindi"];
    notes.push("Maths");
    show(notes.length);
14. 14.True or false: notes to read offline fits saving on the phone. (a) True (b) False
15. 15.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
16. 16.💾 What number does this code show?
    let coins = 9;
    coins = coins - 1;
    coins = coins + 1;
    show(coins);
17. 17.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the phone is lost (d) the screen turns off
18. 18.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 0 (d) 10
19. 19.💾 What is a variable? (a) a phone setting (b) a picture (c) a type of screen (d) a named box for a value
20. 20.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) use it on any device (c) never need a password (d) skip the internet
21. 21.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
22. 22.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Rain (c) Kites
23. 23.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Aman", "Zoya", "Kabir"];
    show(friends[1]); (a) Arjun (b) Aman (c) Riya (d) Zoya
24. 24.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
25. 25.Which of these fits saving on the phone? (a) a class leaderboard (b) a shared to-do list (c) a draft you are typing (d) chat messages to friends
26. 26.💾 What number does this code show?
    let friends = ["Zoya", "Arjun", "Kabir", "Aman"];
    friends.push("Riya");
    friends.push("Meera");
    show(friends.length);
27. 27.💾 What number does this code show?
    let songs = ["Rain", "Sunrise", "Ocean"];
    songs.push("Monsoon");
    songs.push("Stars");
    show(songs.length);
28. 28.💾 What number does this code show?
    let notes = ["Science", "Maths"];
    notes.push("Music");
    notes.push("Sports");
    show(notes.length);
29. 29.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) photos on two devices
30. 30.💾 What number does this code show?
    let friends = ["Meera", "Zoya", "Kabir", "Aman"];
    friends.push("Riya");
    show(friends.length);
31. 31.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Aman", "Kabir", "Zoya", "Riya"];
    show(friends[1]); (a) Meera (b) Kabir (c) Aman (d) Zoya
32. 32.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Sports", "Maths"];
    show(notes[2]); (a) Sports (b) Maths (c) Science
33. 33.💾 What number does this code show?
    let songs = ["Sunrise", "Kites"];
    songs.push("Rain");
    show(songs.length);
34. 34.💾 What number does this code show?
    let notes = ["Sports", "Music"];
    notes.push("Science");
    notes.push("Hindi");
    show(notes.length);
35. 35.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
36. 36.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Stars", "Kites"];
    show(songs[2]); (a) Ocean (b) Kites (c) Stars
37. 37.💾 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
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Stars", "Rain", "Sunrise", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Stars (c) Ocean (d) Sunrise
39. 39.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
40. 40.Which of these fits saving in the cloud? (a) your last game level (b) chat messages to friends (c) a draft you are typing (d) the sound on/off setting

Free app development lessons, practice and worksheets at talentjr.in/app-development-for-students