App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 801 · 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) a cloud leaderboard (b) a shared chat (c) a cloud backup (d) data saved on the phone
2. 2.💾 What does this code show? (Positions start at 0.)
   let songs = ["Stars", "Ocean", "Monsoon"];
   show(songs[1]); (a) Ocean (b) Monsoon (c) Stars
3. 3.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
4. 4.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) photos on two devices (d) notes to read offline
5. 5.💾 What number does this code show?
   let lives = 8;
   lives = lives - 1;
   lives = lives + 2;
   show(lives);
6. 6.💾 What is a variable? (a) a named box for a value (b) a picture (c) a type of screen (d) a phone setting
7. 7.💾 What number does this code show?
   let notes = ["Science", "Hindi", "Maths"];
   notes.push("Music");
   notes.push("Art");
   show(notes.length);
8. 8.💾 What does this code show? (Positions start at 0.)
   let songs = ["Sunrise", "Kites", "Rain", "Monsoon", "Ocean"];
   show(songs[2]); (a) Monsoon (b) Rain (c) Sunrise (d) Kites
9. 9.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
10. 10.💾 What number does this code show?
    let songs = ["Rain", "Sunrise", "Ocean", "Stars"];
    songs.push("Monsoon");
    show(songs.length);
11. 11.💾 What number does this code show?
    let coins = 4;
    coins = coins - 4;
    coins = coins + 5;
    show(coins);
12. 12.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) shrink the app (c) skip the internet (d) never need a password
13. 13.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Sunrise", "Kites", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Ocean (d) Rain
14. 14.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 shared to-do list
15. 15.💾 What number does this code show?
    let songs = ["Stars", "Monsoon"];
    songs.push("Ocean");
    show(songs.length);
16. 16.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 0 (d) 1
17. 17.True or false: notes to read offline fits saving on the phone. (a) True (b) False
18. 18.💾 What number does this code show?
    let friends = ["Riya", "Zoya", "Aman"];
    friends.push("Meera");
    show(friends.length);
19. 19.Which of these fits saving in the cloud? (a) a class leaderboard (b) your last game level (c) the sound on/off setting (d) a draft you are typing
20. 20.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) you send a message (c) the app is closed (d) the screen turns off
21. 21.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) a class leaderboard (d) the sound on/off setting
22. 22.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) your last game level (d) photos on two devices
23. 23.💾 What number does this code show?
    let coins = 5;
    coins = coins - 3;
    coins = coins + 4;
    show(coins);
24. 24.💾 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
25. 25.💾 What number does this code show?
    let stars = 3;
    stars = stars - 3;
    stars = stars + 4;
    show(stars);
26. 26.💾 Which can hold many values in order? (a) a list (b) a switch (c) a button (d) a single number
27. 27.💾 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
28. 28.💾 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
29. 29.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
30. 30.💾 What number does this code show?
    let friends = ["Riya", "Kabir", "Zoya"];
    friends.push("Aman");
    friends.push("Arjun");
    show(friends.length);
31. 31.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
32. 32.💾 What number does this code show?
    let songs = ["Monsoon", "Stars", "Rain", "Sunrise"];
    songs.push("Ocean");
    songs.push("Kites");
    show(songs.length);
33. 33.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Stars", "Sunrise", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Ocean (d) Rain
34. 34.💾 What number does this code show?
    let stars = 8;
    stars = stars - 5;
    stars = stars + 2;
    show(stars);
35. 35.💾 What number does this code show?
    let friends = ["Riya", "Zoya"];
    friends.push("Arjun");
    show(friends.length);
36. 36.True or false: photos on two devices fits saving on the phone. (a) True (b) False
37. 37.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
38. 38.💾 What number does this code show?
    let notes = ["Art", "Maths", "Science"];
    notes.push("Sports");
    notes.push("Hindi");
    show(notes.length);
39. 39.Which of these fits saving on the phone? (a) a draft you are typing (b) chat messages to friends (c) a shared to-do list (d) photos on two devices
40. 40.True or false: your last game level fits saving on the phone. (a) False (b) True

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