App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 440 · 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: notes to read offline fits saving in the cloud. (a) True (b) False
2. 2.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
3. 3.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the app is closed (d) the phone is lost
4. 4.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 0 (d) 1
5. 5.💾 pop() takes off the last item. What does this code show?
   let songs = ["Sunrise", "Ocean", "Rain", "Stars", "Monsoon"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Stars (b) Ocean (c) Rain (d) Sunrise
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 notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
8. 8.💾 What number does this code show?
   let lives = 5;
   lives = lives - 2;
   lives = lives + 4;
   show(lives);
9. 9.Which of these fits saving on the phone? (a) chat messages to friends (b) a shared to-do list (c) your last game level (d) a class leaderboard
10. 10.💾 What number does this code show?
    let coins = 4;
    coins = coins - 1;
    coins = coins + 3;
    show(coins);
11. 11.💾 Which works with no internet at all? (a) a shared chat (b) a cloud backup (c) a cloud leaderboard (d) data saved on the phone
12. 12.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) notes to read offline (d) chat messages to friends
13. 13.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) skip the internet (d) use it on any device
14. 14.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Hindi", "Sports", "Music"];
    show(notes[0]); (a) Hindi (b) Music (c) Science (d) Sports
15. 15.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
16. 16.💾 What number does this code show?
    let score = 4;
    score = score - 3;
    score = score + 4;
    show(score);
17. 17.💾 What number does this code show?
    let score = 4;
    score = score - 2;
    score = score + 2;
    show(score);
18. 18.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 4;
    show(coins);
19. 19.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a draft you are typing (d) photos on two devices
20. 20.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Maths", "Sports", "Science", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Sports (c) Maths (d) Science
21. 21.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Stars (c) Monsoon
22. 22.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
23. 23.💾 What number does this code show?
    let stars = 4;
    stars = stars - 1;
    stars = stars + 1;
    show(stars);
24. 24.💾 What number does this code show?
    let friends = ["Arjun", "Riya"];
    friends.push("Kabir");
    friends.push("Zoya");
    show(friends.length);
25. 25.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
26. 26.💾 What number does this code show?
    let friends = ["Meera", "Riya", "Kabir", "Zoya"];
    friends.push("Aman");
    show(friends.length);
27. 27.💾 What is a variable? (a) a named box for a value (b) a phone setting (c) a picture (d) a type of screen
28. 28.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Sports", "Maths"];
    show(notes[2]); (a) Sports (b) Hindi (c) Maths
29. 29.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) the sound on/off setting (d) a class leaderboard
30. 30.💾 What number does this code show?
    let points = 6;
    points = points - 4;
    points = points + 1;
    show(points);
31. 31.💾 What number does this code show?
    let songs = ["Sunrise", "Monsoon"];
    songs.push("Rain");
    songs.push("Stars");
    show(songs.length);
32. 32.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Sunrise", "Kites", "Ocean"];
    show(songs[3]); (a) Kites (b) Monsoon (c) Ocean (d) Sunrise
33. 33.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
34. 34.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
35. 35.💾 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
36. 36.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
37. 37.💾 What number does this code show?
    let friends = ["Kabir", "Aman", "Arjun", "Riya"];
    friends.push("Meera");
    friends.push("Zoya");
    show(friends.length);
38. 38.💾 What number does this code show?
    let points = 9;
    points = points - 1;
    points = points + 3;
    show(points);
39. 39.💾 What number does this code show?
    let friends = ["Kabir", "Aman", "Meera"];
    friends.push("Riya");
    show(friends.length);
40. 40.💾 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

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