App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 316 · 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 photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
2. 2.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
3. 3.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
4. 4.💾 Which can hold many values in order? (a) a switch (b) a button (c) a single number (d) a list
5. 5.Which of these fits saving in the cloud? (a) a shared to-do list (b) the sound on/off setting (c) your last game level (d) a draft you are typing
6. 6.💾 What number does this code show?
   let notes = ["Music", "Hindi", "Science", "Sports"];
   notes.push("Art");
   show(notes.length);
7. 7.💾 What does this code show? (Positions start at 0.)
   let friends = ["Arjun", "Kabir", "Riya"];
   show(friends[0]); (a) Kabir (b) Arjun (c) Riya
8. 8.💾 What number does this code show?
   let songs = ["Monsoon", "Kites", "Sunrise"];
   songs.push("Stars");
   show(songs.length);
9. 9.💾 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
10. 10.💾 What number does this code show?
    let coins = 3;
    coins = coins - 1;
    coins = coins + 3;
    show(coins);
11. 11.💾 What number does this code show?
    let coins = 3;
    coins = coins - 2;
    coins = coins + 5;
    show(coins);
12. 12.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
13. 13.💾 What number does this code show?
    let friends = ["Meera", "Kabir"];
    friends.push("Riya");
    friends.push("Aman");
    show(friends.length);
14. 14.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Aman", "Zoya", "Kabir", "Meera"];
    show(friends[1]); (a) Riya (b) Kabir (c) Zoya (d) Aman
15. 15.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Riya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Riya (c) Meera
16. 16.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
17. 17.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
18. 18.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Monsoon", "Rain"];
    show(songs[1]); (a) Rain (b) Kites (c) Monsoon (d) Sunrise
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.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) a class leaderboard (d) notes to read offline
21. 21.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) never need a password (d) use it on any device
22. 22.True or false: photos on two devices fits saving on the phone. (a) True (b) False
23. 23.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
24. 24.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a class leaderboard (d) the sound on/off setting
25. 25.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Music", "Art", "Science", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Art (c) Science (d) Maths
26. 26.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a class leaderboard (d) your last game level
27. 27.Which of these fits saving in the cloud? (a) your last game level (b) chat messages to friends (c) the sound on/off setting (d) notes to read offline
28. 28.💾 What number does this code show?
    let lives = 5;
    lives = lives - 3;
    lives = lives + 4;
    show(lives);
29. 29.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
30. 30.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
31. 31.True or false: your last game level fits saving in the cloud. (a) False (b) True
32. 32.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) data saved on the phone (d) a shared chat
33. 33.💾 What number does this code show?
    let friends = ["Meera", "Arjun", "Kabir", "Zoya"];
    friends.push("Riya");
    friends.push("Aman");
    show(friends.length);
34. 34.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
35. 35.💾 What number does this code show?
    let score = 5;
    score = score - 1;
    score = score + 5;
    show(score);
36. 36.💾 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
37. 37.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Sunrise", "Stars", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Ocean (c) Rain (d) Sunrise
38. 38.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
39. 39.💾 What number does this code show?
    let stars = 6;
    stars = stars - 4;
    stars = stars + 2;
    show(stars);
40. 40.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Sports", "Art"];
    show(notes[0]); (a) Music (b) Sports (c) Art

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