App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 438 · 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 of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) a shared to-do list (d) the sound on/off setting
2. 2.💾 What number does this code show?
   let notes = ["Maths", "Science", "Music"];
   notes.push("Sports");
   notes.push("Hindi");
   show(notes.length);
3. 3.💾 What number does this code show?
   let notes = ["Music", "Sports", "Art"];
   notes.push("Hindi");
   notes.push("Maths");
   show(notes.length);
4. 4.💾 What number does this code show?
   let notes = ["Science", "Art", "Music", "Maths"];
   notes.push("Hindi");
   show(notes.length);
5. 5.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Monsoon", "Rain", "Kites"];
   show(songs[2]); (a) Ocean (b) Monsoon (c) Rain (d) Kites
6. 6.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a picture (d) a named box for a value
7. 7.💾 What number does this code show?
   let stars = 3;
   stars = stars - 2;
   stars = stars + 3;
   show(stars);
8. 8.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.💾 What number does this code show?
   let notes = ["Art", "Music", "Science"];
   notes.push("Maths");
   show(notes.length);
10. 10.💾 Which can hold many values in order? (a) a button (b) a single number (c) a switch (d) a list
11. 11.💾 What number does this code show?
    let score = 4;
    score = score - 1;
    score = score + 2;
    show(score);
12. 12.💾 What number does this code show?
    let songs = ["Sunrise", "Monsoon", "Rain", "Stars"];
    songs.push("Ocean");
    show(songs.length);
13. 13.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) photos on two devices (d) a draft you are typing
14. 14.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Riya", "Aman", "Meera", "Zoya"];
    show(friends[4]); (a) Zoya (b) Aman (c) Kabir (d) Riya
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Art", "Science", "Maths", "Music"];
    show(notes[2]); (a) Maths (b) Science (c) Sports (d) Art
16. 16.💾 What number does this code show?
    let friends = ["Kabir", "Arjun", "Riya"];
    friends.push("Zoya");
    friends.push("Meera");
    show(friends.length);
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.💾 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
19. 19.💾 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
20. 20.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 10 (d) 0
21. 21.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) skip the internet (c) never need a password (d) use it on any device
22. 22.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Meera", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Arjun (c) Meera
23. 23.Which of these fits saving on the phone? (a) notes to read offline (b) a shared to-do list (c) photos on two devices (d) chat messages to friends
24. 24.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
25. 25.💾 What number does this code show?
    let songs = ["Sunrise", "Rain"];
    songs.push("Monsoon");
    songs.push("Kites");
    show(songs.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 your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
28. 28.💾 What number does this code show?
    let songs = ["Monsoon", "Sunrise"];
    songs.push("Stars");
    show(songs.length);
29. 29.💾 What number does this code show?
    let notes = ["Maths", "Science", "Art"];
    notes.push("Sports");
    notes.push("Hindi");
    show(notes.length);
30. 30.Which of these fits saving on the phone? (a) your last game level (b) chat messages to friends (c) a class leaderboard (d) photos on two devices
31. 31.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
32. 32.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Monsoon", "Kites", "Ocean", "Sunrise"];
    show(songs[2]); (a) Ocean (b) Kites (c) Monsoon (d) Stars
33. 33.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
34. 34.💾 What number does this code show?
    let score = 4;
    score = score - 4;
    score = score + 4;
    show(score);
35. 35.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) chat messages to friends (d) a draft you are typing
36. 36.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Kabir", "Arjun", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Arjun (d) Aman
37. 37.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
38. 38.💾 Which works with no internet at all? (a) data saved on the phone (b) a shared chat (c) a cloud leaderboard (d) a cloud backup
39. 39.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
40. 40.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

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