App Dev Worksheet: Variables, Lists and Saving

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