App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 6 · 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: photos on two devices fits saving in the cloud. (a) False (b) True
2. 2.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) skip the internet (d) use it on any device
3. 3.💾 What does this code show? (Positions start at 0.)
   let notes = ["Music", "Hindi", "Science", "Art"];
   show(notes[3]); (a) Hindi (b) Art (c) Science (d) Music
4. 4.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
5. 5.💾 What number does this code show?
   let friends = ["Zoya", "Meera", "Aman", "Arjun"];
   friends.push("Kabir");
   friends.push("Riya");
   show(friends.length);
6. 6.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a shared to-do list (d) a draft you are typing
7. 7.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the app is closed (c) the phone is lost (d) the screen turns off
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.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
10. 10.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Zoya", "Kabir"];
    show(friends[1]); (a) Meera (b) Zoya (c) Kabir
11. 11.True or false: photos on two devices fits saving on the phone. (a) False (b) True
12. 12.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
13. 13.💾 What number does this code show?
    let friends = ["Kabir", "Aman"];
    friends.push("Zoya");
    show(friends.length);
14. 14.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Riya", "Meera", "Kabir", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Kabir (c) Meera (d) Zoya
15. 15.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Arjun", "Meera", "Kabir"];
    show(friends[2]); (a) Riya (b) Arjun (c) Meera (d) Aman
16. 16.💾 What number does this code show?
    let notes = ["Science", "Maths", "Sports", "Art"];
    notes.push("Hindi");
    show(notes.length);
17. 17.💾 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
18. 18.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
19. 19.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a shared to-do list (d) your last game level
20. 20.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) chat messages to friends (d) the sound on/off setting
21. 21.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) the sound on/off setting (d) a class leaderboard
22. 22.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
23. 23.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
24. 24.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Arjun", "Aman", "Meera"];
    show(friends[2]); (a) Zoya (b) Arjun (c) Aman (d) Meera
25. 25.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Science", "Sports", "Maths"];
    show(notes[4]); (a) Music (b) Science (c) Maths (d) Art
26. 26.💾 What number does this code show?
    let lives = 8;
    lives = lives - 5;
    lives = lives + 4;
    show(lives);
27. 27.💾 What number does this code show?
    let lives = 5;
    lives = lives - 5;
    lives = lives + 2;
    show(lives);
28. 28.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
29. 29.💾 What number does this code show?
    let lives = 3;
    lives = lives - 3;
    lives = lives + 2;
    show(lives);
30. 30.💾 What number does this code show?
    let coins = 3;
    coins = coins - 1;
    coins = coins + 2;
    show(coins);
31. 31.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
32. 32.💾 What number does this code show?
    let songs = ["Monsoon", "Kites"];
    songs.push("Sunrise");
    songs.push("Ocean");
    show(songs.length);
33. 33.True or false: notes to read offline fits saving on the phone. (a) False (b) True
34. 34.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
35. 35.Which of these fits saving on the phone? (a) photos on two devices (b) a draft you are typing (c) a class leaderboard (d) a shared to-do list
36. 36.💾 What number does this code show?
    let songs = ["Stars", "Monsoon", "Kites"];
    songs.push("Ocean");
    songs.push("Rain");
    show(songs.length);
37. 37.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
38. 38.Which of these fits saving in the cloud? (a) photos on two devices (b) notes to read offline (c) the sound on/off setting (d) your last game level
39. 39.💾 Which can hold many values in order? (a) a button (b) a single number (c) a list (d) a switch
40. 40.💾 What number does this code show?
    let score = 5;
    score = score - 5;
    score = score + 4;
    show(score);

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