App Dev Worksheet: Variables, Lists and Saving

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

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