App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 375 · 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.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the app is closed (c) the screen turns off (d) the phone is lost
2. 2.💾 What number does this code show?
   let notes = ["Music", "Sports", "Maths", "Art"];
   notes.push("Hindi");
   show(notes.length);
3. 3.💾 What number does this code show?
   let points = 8;
   points = points - 8;
   points = points + 5;
   show(points);
4. 4.💾 What number does this code show?
   let coins = 8;
   coins = coins - 4;
   coins = coins + 1;
   show(coins);
5. 5.True or false: your last game level fits saving on the phone. (a) False (b) True
6. 6.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
7. 7.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
8. 8.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.💾 What is a variable? (a) a named box for a value (b) a picture (c) a type of screen (d) a phone setting
10. 10.💾 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
11. 11.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 2;
    show(score);
12. 12.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
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.💾 What number does this code show?
    let notes = ["Sports", "Maths", "Science", "Music"];
    notes.push("Art");
    notes.push("Hindi");
    show(notes.length);
15. 15.💾 What number does this code show?
    let notes = ["Music", "Maths", "Science"];
    notes.push("Art");
    notes.push("Sports");
    show(notes.length);
16. 16.💾 What number does this code show?
    let friends = ["Aman", "Kabir", "Riya"];
    friends.push("Zoya");
    friends.push("Arjun");
    show(friends.length);
17. 17.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Aman", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Riya
18. 18.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) a shared chat (d) data saved on the phone
19. 19.💾 What number does this code show?
    let stars = 8;
    stars = stars - 1;
    stars = stars + 3;
    show(stars);
20. 20.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) use it on any device (d) never need a password
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Aman", "Riya", "Meera"];
    show(friends[1]); (a) Riya (b) Meera (c) Kabir (d) Aman
22. 22.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Rain", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Ocean (c) Rain
23. 23.💾 What number does this code show?
    let friends = ["Zoya", "Meera"];
    friends.push("Kabir");
    show(friends.length);
24. 24.Which of these fits saving in the cloud? (a) chat messages to friends (b) the sound on/off setting (c) your last game level (d) a draft you are typing
25. 25.💾 What number does this code show?
    let notes = ["Music", "Maths", "Art", "Science"];
    notes.push("Hindi");
    notes.push("Sports");
    show(notes.length);
26. 26.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
27. 27.💾 What number does this code show?
    let notes = ["Science", "Music"];
    notes.push("Maths");
    show(notes.length);
28. 28.Which of these fits saving on the phone? (a) your last game level (b) a class leaderboard (c) a shared to-do list (d) photos on two devices
29. 29.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
30. 30.💾 What number does this code show?
    let friends = ["Kabir", "Zoya", "Riya"];
    friends.push("Arjun");
    show(friends.length);
31. 31.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Kites", "Rain", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Monsoon (d) Stars
32. 32.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
33. 33.Which of these fits saving on the phone? (a) the sound on/off setting (b) a class leaderboard (c) chat messages to friends (d) a shared to-do list
34. 34.💾 What number does this code show?
    let coins = 6;
    coins = coins - 3;
    coins = coins + 5;
    show(coins);
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Rain", "Stars", "Monsoon", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Monsoon (c) Rain (d) Kites
36. 36.💾 What number does this code show?
    let lives = 3;
    lives = lives - 3;
    lives = lives + 5;
    show(lives);
37. 37.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
38. 38.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a shared to-do list (c) notes to read offline (d) your last game level
39. 39.💾 What number does this code show?
    let stars = 3;
    stars = stars - 2;
    stars = stars + 1;
    show(stars);
40. 40.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Ocean", "Sunrise"];
    show(songs[0]); (a) Sunrise (b) Ocean (c) Rain (d) Monsoon

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