App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 505 · 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 songs = ["Ocean", "Kites", "Monsoon", "Rain"];
   songs.push("Stars");
   show(songs.length);
2. 2.💾 pop() takes off the last item. What does this code show?
   let songs = ["Rain", "Ocean", "Monsoon", "Stars"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Stars (b) Monsoon (c) Rain (d) Ocean
3. 3.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
4. 4.💾 What number does this code show?
   let songs = ["Kites", "Sunrise", "Monsoon"];
   songs.push("Rain");
   show(songs.length);
5. 5.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a shared to-do list (c) notes to read offline (d) your last game level
6. 6.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Music", "Art", "Science", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Maths (b) Art (c) Science (d) Music
7. 7.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) your last game level
8. 8.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.Which of these fits saving in the cloud? (a) the sound on/off setting (b) chat messages to friends (c) a draft you are typing (d) your last game level
10. 10.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Rain", "Monsoon", "Sunrise", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Rain (c) Ocean (d) Monsoon
11. 11.💾 What number does this code show?
    let score = 5;
    score = score - 5;
    score = score + 1;
    show(score);
12. 12.💾 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
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.💾 What number does this code show?
    let notes = ["Art", "Music", "Maths"];
    notes.push("Science");
    show(notes.length);
15. 15.True or false: your last game level fits saving on the phone. (a) False (b) True
16. 16.💾 What number does this code show?
    let stars = 3;
    stars = stars - 3;
    stars = stars + 4;
    show(stars);
17. 17.💾 What number does this code show?
    let coins = 4;
    coins = coins - 2;
    coins = coins + 1;
    show(coins);
18. 18.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Art"];
    show(notes[2]); (a) Maths (b) Music (c) Art
19. 19.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) your last game level (d) a class leaderboard
20. 20.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a shared chat (c) a cloud backup (d) data saved on the phone
21. 21.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 0 (d) 2
22. 22.💾 What number does this code show?
    let friends = ["Zoya", "Meera", "Kabir"];
    friends.push("Arjun");
    show(friends.length);
23. 23.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) the sound on/off setting (d) a shared to-do list
24. 24.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Rain", "Monsoon"];
    show(songs[2]); (a) Kites (b) Rain (c) Monsoon
25. 25.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
26. 26.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
27. 27.💾 What number does this code show?
    let notes = ["Hindi", "Maths"];
    notes.push("Art");
    notes.push("Science");
    show(notes.length);
28. 28.💾 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
29. 29.💾 What is a variable? (a) a named box for a value (b) a phone setting (c) a type of screen (d) a picture
30. 30.💾 What number does this code show?
    let notes = ["Maths", "Sports", "Music", "Art"];
    notes.push("Hindi");
    notes.push("Science");
    show(notes.length);
31. 31.💾 What number does this code show?
    let coins = 4;
    coins = coins - 1;
    coins = coins + 2;
    show(coins);
32. 32.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
33. 33.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Kabir", "Aman", "Zoya", "Arjun"];
    show(friends[1]); (a) Meera (b) Aman (c) Kabir (d) Zoya
34. 34.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
35. 35.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Kites", "Ocean", "Stars", "Monsoon"];
    show(songs[0]); (a) Stars (b) Ocean (c) Rain (d) Kites
36. 36.💾 What number does this code show?
    let songs = ["Rain", "Stars", "Sunrise"];
    songs.push("Monsoon");
    show(songs.length);
37. 37.💾 What number does this code show?
    let lives = 5;
    lives = lives - 3;
    lives = lives + 3;
    show(lives);
38. 38.💾 What number does this code show?
    let points = 6;
    points = points - 4;
    points = points + 2;
    show(points);
39. 39.💾 What number does this code show?
    let score = 7;
    score = score - 7;
    score = score + 1;
    show(score);
40. 40.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone

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