App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 825 · 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) the phone is lost (b) the app is closed (c) you send a message (d) the screen turns off
2. 2.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) on the phone (b) in the cloud
3. 3.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
4. 4.True or false: notes to read offline fits saving on the phone. (a) False (b) True
5. 5.Which of these fits saving on the phone? (a) the sound on/off setting (b) a class leaderboard (c) chat messages to friends (d) photos on two devices
6. 6.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.💾 What is a variable? (a) a type of screen (b) a phone setting (c) a picture (d) a named box for a value
8. 8.💾 pop() takes off the last item. What does this code show?
   let friends = ["Zoya", "Aman", "Riya", "Arjun", "Meera"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Riya (b) Zoya (c) Aman (d) Arjun
9. 9.💾 What number does this code show?
   let stars = 6;
   stars = stars - 2;
   stars = stars + 3;
   show(stars);
10. 10.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) chat messages to friends (d) a draft you are typing
11. 11.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) a shared to-do list (d) photos on two devices
12. 12.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Music"];
    show(notes[1]); (a) Music (b) Art (c) Maths
13. 13.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud leaderboard (c) a shared chat (d) a cloud backup
14. 14.💾 What number does this code show?
    let friends = ["Aman", "Meera", "Riya"];
    friends.push("Kabir");
    show(friends.length);
15. 15.💾 What number does this code show?
    let stars = 8;
    stars = stars - 5;
    stars = stars + 2;
    show(stars);
16. 16.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) never need a password (d) use it on any device
17. 17.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) your last game level (d) photos on two devices
18. 18.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
19. 19.💾 What number does this code show?
    let points = 6;
    points = points - 5;
    points = points + 4;
    show(points);
20. 20.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
21. 21.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) your last game level (d) chat messages to friends
22. 22.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
23. 23.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
24. 24.💾 Which can hold many values in order? (a) a single number (b) a list (c) a button (d) a switch
25. 25.💾 What number does this code show?
    let stars = 5;
    stars = stars - 3;
    stars = stars + 2;
    show(stars);
26. 26.💾 What number does this code show?
    let friends = ["Aman", "Meera"];
    friends.push("Zoya");
    show(friends.length);
27. 27.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Science"];
    show(notes[0]); (a) Maths (b) Science (c) Art
28. 28.💾 What number does this code show?
    let score = 9;
    score = score - 2;
    score = score + 5;
    show(score);
29. 29.💾 What number does this code show?
    let songs = ["Sunrise", "Ocean"];
    songs.push("Kites");
    songs.push("Rain");
    show(songs.length);
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Hindi", "Music"];
    show(notes[1]); (a) Music (b) Hindi (c) Science
31. 31.True or false: your last game level fits saving on the phone. (a) True (b) False
32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Riya", "Arjun", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Riya (c) Kabir (d) Arjun
33. 33.💾 What number does this code show?
    let notes = ["Hindi", "Sports", "Science", "Art"];
    notes.push("Music");
    show(notes.length);
34. 34.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Kites", "Ocean"];
    show(songs[0]); (a) Kites (b) Ocean (c) Monsoon
35. 35.💾 What number does this code show?
    let stars = 4;
    stars = stars - 3;
    stars = stars + 4;
    show(stars);
36. 36.💾 What number does this code show?
    let stars = 5;
    stars = stars - 4;
    stars = stars + 4;
    show(stars);
37. 37.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) notes to read offline (d) a class leaderboard
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Kites", "Ocean", "Rain", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Ocean (c) Rain (d) Kites
39. 39.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
40. 40.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True

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