App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 259 · 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 class leaderboard fits saving in the cloud. (a) True (b) False
2. 2.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the phone is lost (d) the app is closed
3. 3.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
4. 4.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) on the phone (b) in the cloud
5. 5.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
6. 6.Which of these fits saving in the cloud? (a) your last game level (b) a class leaderboard (c) notes to read offline (d) the sound on/off setting
7. 7.💾 What number does this code show?
   let songs = ["Monsoon", "Rain", "Stars", "Sunrise"];
   songs.push("Kites");
   songs.push("Ocean");
   show(songs.length);
8. 8.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
9. 9.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) the sound on/off setting (d) a class leaderboard
10. 10.💾 What number does this code show?
    let points = 3;
    points = points - 1;
    points = points + 1;
    show(points);
11. 11.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Rain", "Stars", "Ocean"];
    show(songs[0]); (a) Monsoon (b) Rain (c) Kites (d) Stars
12. 12.💾 What number does this code show?
    let notes = ["Music", "Sports"];
    notes.push("Maths");
    show(notes.length);
13. 13.💾 What is a variable? (a) a type of screen (b) a picture (c) a named box for a value (d) a phone setting
14. 14.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Rain", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Ocean (c) Stars
15. 15.Which of these fits saving in the cloud? (a) photos on two devices (b) your last game level (c) notes to read offline (d) a draft you are typing
16. 16.💾 What number does this code show?
    let stars = 4;
    stars = stars - 1;
    stars = stars + 4;
    show(stars);
17. 17.💾 What number does this code show?
    let coins = 5;
    coins = coins - 4;
    coins = coins + 5;
    show(coins);
18. 18.💾 What number does this code show?
    let lives = 9;
    lives = lives - 3;
    lives = lives + 3;
    show(lives);
19. 19.💾 What number does this code show?
    let notes = ["Maths", "Hindi"];
    notes.push("Science");
    show(notes.length);
20. 20.💾 What number does this code show?
    let songs = ["Kites", "Rain"];
    songs.push("Sunrise");
    show(songs.length);
21. 21.💾 What number does this code show?
    let notes = ["Sports", "Science", "Maths", "Hindi"];
    notes.push("Music");
    notes.push("Art");
    show(notes.length);
22. 22.True or false: your last game level fits saving on the phone. (a) False (b) True
23. 23.True or false: notes to read offline fits saving on the phone. (a) True (b) False
24. 24.💾 What number does this code show?
    let friends = ["Riya", "Zoya"];
    friends.push("Arjun");
    show(friends.length);
25. 25.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) your last game level (d) chat messages to friends
26. 26.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Monsoon", "Rain", "Kites", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Monsoon (c) Ocean (d) Rain
27. 27.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) notes to read offline (d) chat messages to friends
28. 28.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Meera", "Riya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Arjun (c) Kabir (d) Meera
29. 29.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
30. 30.💾 What number does this code show?
    let songs = ["Sunrise", "Rain", "Ocean", "Kites"];
    songs.push("Monsoon");
    show(songs.length);
31. 31.💾 What number does this code show?
    let stars = 7;
    stars = stars - 7;
    stars = stars + 2;
    show(stars);
32. 32.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Rain", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Ocean (c) Rain (d) Stars
33. 33.💾 What number does this code show?
    let points = 5;
    points = points - 3;
    points = points + 5;
    show(points);
34. 34.💾 What number does this code show?
    let notes = ["Maths", "Art"];
    notes.push("Hindi");
    notes.push("Music");
    show(notes.length);
35. 35.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
36. 36.💾 What number does this code show?
    let score = 8;
    score = score - 3;
    score = score + 3;
    show(score);
37. 37.💾 What number does this code show?
    let lives = 4;
    lives = lives - 2;
    lives = lives + 2;
    show(lives);
38. 38.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
39. 39.💾 What number does this code show?
    let songs = ["Sunrise", "Rain"];
    songs.push("Ocean");
    songs.push("Stars");
    show(songs.length);
40. 40.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) a shared chat (d) data saved on the phone

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