App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 745 · 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 a draft you are typing: on the phone or in the cloud? (a) in the cloud (b) on the phone
2. 2.Which of these fits saving on the phone? (a) a class leaderboard (b) the sound on/off setting (c) chat messages to friends (d) a shared to-do list
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Monsoon", "Rain", "Kites", "Sunrise"];
   show(songs[2]); (a) Monsoon (b) Kites (c) Sunrise (d) Rain
4. 4.💾 pop() takes off the last item. What does this code show?
   let songs = ["Sunrise", "Rain", "Monsoon", "Ocean"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Monsoon (d) Sunrise
5. 5.💾 What number does this code show?
   let songs = ["Monsoon", "Ocean"];
   songs.push("Rain");
   show(songs.length);
6. 6.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
7. 7.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) a shared to-do list (d) a draft you are typing
8. 8.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 10 (d) 0
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) notes to read offline
11. 11.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
13. 13.💾 What is a variable? (a) a picture (b) a phone setting (c) a named box for a value (d) a type of screen
14. 14.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Hindi (c) Sports
15. 15.💾 Saving data in the cloud lets you ___. (a) never need a password (b) use it on any device (c) skip the internet (d) shrink the app
16. 16.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
17. 17.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) photos on two devices (d) notes to read offline
18. 18.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
19. 19.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Sunrise", "Kites", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Kites (d) Sunrise
20. 20.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) a class leaderboard
21. 21.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
22. 22.💾 What number does this code show?
    let coins = 9;
    coins = coins - 5;
    coins = coins + 4;
    show(coins);
23. 23.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
24. 24.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
25. 25.Which of these fits saving in the cloud? (a) a shared to-do list (b) your last game level (c) the sound on/off setting (d) a draft you are typing
26. 26.💾 What number does this code show?
    let notes = ["Maths", "Sports"];
    notes.push("Music");
    notes.push("Science");
    show(notes.length);
27. 27.💾 What number does this code show?
    let songs = ["Stars", "Kites"];
    songs.push("Rain");
    songs.push("Ocean");
    show(songs.length);
28. 28.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Stars", "Kites", "Ocean", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Sunrise (c) Stars (d) Ocean
29. 29.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Ocean", "Kites", "Sunrise"];
    show(songs[3]); (a) Kites (b) Rain (c) Ocean (d) Monsoon
30. 30.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
31. 31.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) you send a message (d) the phone is lost
32. 32.💾 What number does this code show?
    let points = 5;
    points = points - 2;
    points = points + 3;
    show(points);
33. 33.💾 What number does this code show?
    let points = 3;
    points = points - 3;
    points = points + 5;
    show(points);
34. 34.💾 What number does this code show?
    let coins = 5;
    coins = coins - 1;
    coins = coins + 3;
    show(coins);
35. 35.Which of these fits saving on the phone? (a) chat messages to friends (b) a shared to-do list (c) photos on two devices (d) your last game level
36. 36.💾 What number does this code show?
    let points = 9;
    points = points - 2;
    points = points + 4;
    show(points);
37. 37.💾 What number does this code show?
    let stars = 6;
    stars = stars - 4;
    stars = stars + 3;
    show(stars);
38. 38.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
39. 39.💾 What number does this code show?
    let songs = ["Stars", "Rain", "Kites", "Sunrise"];
    songs.push("Ocean");
    songs.push("Monsoon");
    show(songs.length);
40. 40.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Kites", "Rain"];
    show(songs[0]); (a) Stars (b) Rain (c) Kites

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