App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 447 · 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.True or false: notes to read offline fits saving on the phone. (a) False (b) True
2. 2.💾 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
3. 3.💾 What does this code show? (Positions start at 0.)
   let notes = ["Hindi", "Science", "Art", "Sports", "Maths"];
   show(notes[1]); (a) Science (b) Art (c) Hindi (d) Sports
4. 4.💾 What number does this code show?
   let songs = ["Rain", "Ocean"];
   songs.push("Kites");
   songs.push("Monsoon");
   show(songs.length);
5. 5.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) chat messages to friends (d) notes to read offline
6. 6.💾 What number does this code show?
   let notes = ["Science", "Hindi"];
   notes.push("Art");
   show(notes.length);
7. 7.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 0 (d) 10
8. 8.💾 What number does this code show?
   let points = 9;
   points = points - 5;
   points = points + 1;
   show(points);
9. 9.Which of these fits saving on the phone? (a) the sound on/off setting (b) photos on two devices (c) a class leaderboard (d) chat messages to friends
10. 10.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) notes to read offline (d) a class leaderboard
11. 11.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
12. 12.True or false: your last game level fits saving on the phone. (a) False (b) True
13. 13.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Zoya", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Kabir (c) Riya (d) Meera
14. 14.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the app is closed (d) the phone is lost
15. 15.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
16. 16.💾 What number does this code show?
    let notes = ["Music", "Sports"];
    notes.push("Science");
    notes.push("Hindi");
    show(notes.length);
17. 17.Which of these fits saving in the cloud? (a) your last game level (b) photos on two devices (c) the sound on/off setting (d) a draft you are typing
18. 18.💾 What number does this code show?
    let songs = ["Monsoon", "Stars", "Sunrise", "Ocean"];
    songs.push("Kites");
    show(songs.length);
19. 19.💾 What is a variable? (a) a type of screen (b) a named box for a value (c) a picture (d) a phone setting
20. 20.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
21. 21.💾 Which can hold many values in order? (a) a button (b) a single number (c) a list (d) a switch
22. 22.💾 What number does this code show?
    let stars = 9;
    stars = stars - 8;
    stars = stars + 5;
    show(stars);
23. 23.💾 What number does this code show?
    let points = 3;
    points = points - 1;
    points = points + 1;
    show(points);
24. 24.💾 What number does this code show?
    let stars = 8;
    stars = stars - 6;
    stars = stars + 5;
    show(stars);
25. 25.💾 What number does this code show?
    let notes = ["Art", "Maths"];
    notes.push("Music");
    notes.push("Science");
    show(notes.length);
26. 26.True or false: photos on two devices fits saving on the phone. (a) True (b) False
27. 27.💾 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
28. 28.💾 What number does this code show?
    let friends = ["Aman", "Arjun"];
    friends.push("Meera");
    show(friends.length);
29. 29.True or false: your last game level fits saving in the cloud. (a) True (b) False
30. 30.💾 What number does this code show?
    let score = 4;
    score = score - 4;
    score = score + 2;
    show(score);
31. 31.Which of these fits saving in the cloud? (a) a class leaderboard (b) your last game level (c) the sound on/off setting (d) notes to read offline
32. 32.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) your last game level (d) a class leaderboard
33. 33.💾 Which works with no internet at all? (a) a shared chat (b) a cloud backup (c) data saved on the phone (d) a cloud leaderboard
34. 34.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Hindi", "Music", "Science", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Science (c) Music (d) Hindi
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Ocean", "Kites", "Rain", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Sunrise (d) Ocean
36. 36.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Kites"];
    show(songs[2]); (a) Kites (b) Monsoon (c) Rain
37. 37.Which of these fits saving in the cloud? (a) a shared to-do list (b) your last game level (c) a draft you are typing (d) the sound on/off setting
38. 38.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
39. 39.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 1;
    show(score);
40. 40.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Monsoon", "Kites", "Stars", "Sunrise"];
    show(songs[1]); (a) Ocean (b) Kites (c) Stars (d) Monsoon

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