App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 854 · 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 lives = 6;
   lives = lives - 4;
   lives = lives + 4;
   show(lives);
2. 2.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 10 (d) 0
3. 3.💾 What does this code show? (Positions start at 0.)
   let friends = ["Arjun", "Riya", "Aman"];
   show(friends[2]); (a) Arjun (b) Riya (c) Aman
4. 4.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
5. 5.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) notes to read offline (d) chat messages to friends
6. 6.💾 What does this code show? (Positions start at 0.)
   let notes = ["Music", "Hindi", "Art"];
   show(notes[1]); (a) Art (b) Music (c) Hindi
7. 7.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Kabir", "Meera", "Riya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Riya (b) Kabir (c) Meera (d) Aman
8. 8.💾 What number does this code show?
   let friends = ["Riya", "Meera"];
   friends.push("Arjun");
   show(friends.length);
9. 9.💾 What number does this code show?
   let coins = 3;
   coins = coins - 1;
   coins = coins + 2;
   show(coins);
10. 10.💾 What number does this code show?
    let stars = 4;
    stars = stars - 3;
    stars = stars + 3;
    show(stars);
11. 11.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) use it on any device (c) skip the internet (d) never need a password
12. 12.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
13. 13.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
14. 14.💾 What number does this code show?
    let friends = ["Aman", "Zoya"];
    friends.push("Arjun");
    friends.push("Riya");
    show(friends.length);
15. 15.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
16. 16.💾 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
17. 17.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
18. 18.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Monsoon", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Ocean (c) Stars
19. 19.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
20. 20.💾 What number does this code show?
    let points = 7;
    points = points - 7;
    points = points + 5;
    show(points);
21. 21.💾 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
22. 22.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
23. 23.True or false: your last game level fits saving on the phone. (a) True (b) False
24. 24.💾 What number does this code show?
    let friends = ["Aman", "Meera"];
    friends.push("Riya");
    friends.push("Zoya");
    show(friends.length);
25. 25.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Zoya", "Aman"];
    show(friends[3]); (a) Kabir (b) Meera (c) Aman (d) Zoya
26. 26.💾 What number does this code show?
    let friends = ["Meera", "Arjun"];
    friends.push("Aman");
    show(friends.length);
27. 27.💾 What number does this code show?
    let friends = ["Riya", "Zoya", "Aman", "Kabir"];
    friends.push("Meera");
    show(friends.length);
28. 28.💾 What number does this code show?
    let lives = 9;
    lives = lives - 3;
    lives = lives + 1;
    show(lives);
29. 29.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a draft you are typing (d) chat messages to friends
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Rain", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Rain
31. 31.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Sunrise", "Monsoon", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Sunrise (c) Rain (d) Stars
32. 32.Which of these fits saving in the cloud? (a) the sound on/off setting (b) photos on two devices (c) notes to read offline (d) a draft you are typing
33. 33.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
34. 34.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a class leaderboard (c) a draft you are typing (d) notes to read offline
35. 35.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Science", "Maths"];
    show(notes[0]); (a) Sports (b) Maths (c) Science
36. 36.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Ocean", "Stars"];
    show(songs[2]); (a) Ocean (b) Rain (c) Stars
37. 37.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Sports", "Hindi", "Science", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Science (c) Maths (d) Hindi
38. 38.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Meera", "Arjun", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Meera (c) Aman (d) Arjun
39. 39.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
40. 40.💾 What number does this code show?
    let notes = ["Music", "Maths", "Science", "Art"];
    notes.push("Hindi");
    notes.push("Sports");
    show(notes.length);

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