App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 143 · 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.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Sports", "Science", "Art", "Music"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Art (b) Sports (c) Science (d) Maths
2. 2.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
3. 3.💾 What does this code show? (Positions start at 0.)
   let notes = ["Sports", "Science", "Music", "Art"];
   show(notes[3]); (a) Music (b) Art (c) Science (d) Sports
4. 4.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the phone is lost (d) the screen turns off
5. 5.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 10 (d) 2
6. 6.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Maths", "Science", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Music (b) Sports (c) Science (d) Maths
7. 7.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
8. 8.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a class leaderboard (d) the sound on/off setting
9. 9.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
10. 10.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Arjun", "Kabir", "Riya", "Aman"];
    show(friends[2]); (a) Kabir (b) Zoya (c) Arjun (d) Riya
11. 11.True or false: your last game level fits saving in the cloud. (a) False (b) True
12. 12.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
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.💾 Saving data in the cloud lets you ___. (a) never need a password (b) use it on any device (c) shrink the app (d) skip the internet
15. 15.💾 What number does this code show?
    let stars = 6;
    stars = stars - 6;
    stars = stars + 5;
    show(stars);
16. 16.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Science", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Music (c) Art
17. 17.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Sports", "Maths"];
    show(notes[0]); (a) Maths (b) Art (c) Sports (d) Science
18. 18.Which of these fits saving on the phone? (a) a class leaderboard (b) a shared to-do list (c) chat messages to friends (d) notes to read offline
19. 19.💾 What number does this code show?
    let score = 6;
    score = score - 6;
    score = score + 1;
    show(score);
20. 20.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
21. 21.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Kites", "Monsoon", "Stars"];
    show(songs[0]); (a) Kites (b) Monsoon (c) Stars (d) Sunrise
22. 22.💾 What number does this code show?
    let notes = ["Art", "Music", "Hindi", "Science"];
    notes.push("Sports");
    show(notes.length);
23. 23.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
24. 24.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
25. 25.True or false: photos on two devices fits saving on the phone. (a) True (b) False
26. 26.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
27. 27.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
28. 28.💾 What number does this code show?
    let songs = ["Rain", "Stars", "Kites"];
    songs.push("Monsoon");
    songs.push("Sunrise");
    show(songs.length);
29. 29.💾 What number does this code show?
    let friends = ["Zoya", "Riya", "Kabir", "Meera"];
    friends.push("Arjun");
    show(friends.length);
30. 30.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Meera", "Kabir", "Riya"];
    show(friends[1]); (a) Riya (b) Arjun (c) Meera (d) Kabir
31. 31.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) a draft you are typing (d) a shared to-do list
32. 32.💾 What number does this code show?
    let notes = ["Hindi", "Music", "Maths"];
    notes.push("Sports");
    show(notes.length);
33. 33.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Stars", "Kites", "Rain"];
    show(songs[3]); (a) Rain (b) Kites (c) Ocean (d) Stars
34. 34.💾 What number does this code show?
    let lives = 7;
    lives = lives - 7;
    lives = lives + 2;
    show(lives);
35. 35.True or false: your last game level fits saving on the phone. (a) True (b) False
36. 36.Which of these fits saving in the cloud? (a) chat messages to friends (b) notes to read offline (c) your last game level (d) a draft you are typing
37. 37.💾 What number does this code show?
    let points = 8;
    points = points - 6;
    points = points + 4;
    show(points);
38. 38.True or false: notes to read offline fits saving on the phone. (a) False (b) True
39. 39.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Stars", "Ocean"];
    show(songs[2]); (a) Sunrise (b) Ocean (c) Stars
40. 40.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False

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