App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 968 · 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.💾 What number does this code show?
   let score = 3;
   score = score - 1;
   score = score + 2;
   show(score);
2. 2.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the app is closed (c) you send a message (d) the phone is lost
3. 3.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
4. 4.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Sports", "Maths", "Art", "Hindi"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Music (c) Art (d) Maths
5. 5.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
7. 7.💾 Which can hold many values in order? (a) a list (b) a single number (c) a button (d) a switch
8. 8.💾 What number does this code show?
   let songs = ["Rain", "Sunrise", "Kites"];
   songs.push("Monsoon");
   show(songs.length);
9. 9.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) never need a password (c) use it on any device (d) shrink the app
10. 10.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Kabir", "Aman"];
    show(friends[2]); (a) Kabir (b) Riya (c) Aman
11. 11.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Hindi", "Maths"];
    show(notes[0]); (a) Sports (b) Hindi (c) Maths
12. 12.💾 What number does this code show?
    let score = 8;
    score = score - 8;
    score = score + 3;
    show(score);
13. 13.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 1 (c) 2 (d) 10
14. 14.💾 What number does this code show?
    let songs = ["Sunrise", "Stars"];
    songs.push("Kites");
    show(songs.length);
15. 15.💾 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
16. 16.💾 What number does this code show?
    let songs = ["Rain", "Monsoon"];
    songs.push("Ocean");
    show(songs.length);
17. 17.True or false: notes to read offline fits saving on the phone. (a) True (b) False
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Zoya", "Aman", "Kabir"];
    show(friends[0]); (a) Aman (b) Zoya (c) Arjun (d) Riya
19. 19.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Arjun", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Arjun (c) Riya
20. 20.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
21. 21.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
22. 22.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
23. 23.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
24. 24.💾 Which works with no internet at all? (a) a shared chat (b) data saved on the phone (c) a cloud leaderboard (d) a cloud backup
25. 25.💾 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
26. 26.💾 What number does this code show?
    let points = 4;
    points = points - 1;
    points = points + 3;
    show(points);
27. 27.💾 What number does this code show?
    let notes = ["Music", "Science", "Hindi", "Maths"];
    notes.push("Art");
    show(notes.length);
28. 28.💾 What number does this code show?
    let songs = ["Ocean", "Sunrise", "Rain", "Kites"];
    songs.push("Stars");
    songs.push("Monsoon");
    show(songs.length);
29. 29.💾 What number does this code show?
    let stars = 5;
    stars = stars - 1;
    stars = stars + 5;
    show(stars);
30. 30.💾 What number does this code show?
    let friends = ["Riya", "Zoya"];
    friends.push("Aman");
    friends.push("Kabir");
    show(friends.length);
31. 31.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
32. 32.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
33. 33.💾 What number does this code show?
    let friends = ["Meera", "Riya", "Aman"];
    friends.push("Zoya");
    show(friends.length);
34. 34.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a type of screen (d) a picture
35. 35.💾 What number does this code show?
    let stars = 3;
    stars = stars - 2;
    stars = stars + 4;
    show(stars);
36. 36.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
37. 37.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
38. 38.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Kabir"];
    show(friends[2]); (a) Arjun (b) Riya (c) Kabir
39. 39.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Maths", "Hindi", "Art", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Hindi (c) Music (d) Art
40. 40.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Stars", "Sunrise", "Rain", "Kites"];
    show(songs[2]); (a) Stars (b) Rain (c) Monsoon (d) Sunrise

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