App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 370 · 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.💾 Saving data in the cloud lets you ___. (a) never need a password (b) skip the internet (c) shrink the app (d) use it on any device
2. 2.💾 What number does this code show?
   let notes = ["Maths", "Music", "Science", "Hindi"];
   notes.push("Sports");
   show(notes.length);
3. 3.💾 What number does this code show?
   let lives = 6;
   lives = lives - 2;
   lives = lives + 2;
   show(lives);
4. 4.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a draft you are typing (d) a class leaderboard
5. 5.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Stars", "Rain"];
   show(songs[0]); (a) Rain (b) Stars (c) Ocean
6. 6.True or false: your last game level fits saving in the cloud. (a) False (b) True
7. 7.💾 What does this code show? (Positions start at 0.)
   let songs = ["Kites", "Monsoon", "Sunrise"];
   show(songs[2]); (a) Kites (b) Monsoon (c) Sunrise
8. 8.True or false: notes to read offline fits saving on the phone. (a) True (b) False
9. 9.💾 What number does this code show?
   let notes = ["Maths", "Music", "Art"];
   notes.push("Hindi");
   notes.push("Sports");
   show(notes.length);
10. 10.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Art", "Maths", "Sports", "Science"];
    show(notes[2]); (a) Music (b) Sports (c) Art (d) Maths
11. 11.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Sports", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Art (c) Science
13. 13.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) notes to read offline (d) photos on two devices
14. 14.Which of these fits saving in the cloud? (a) your last game level (b) a shared to-do list (c) notes to read offline (d) a draft you are typing
15. 15.💾 What is a variable? (a) a picture (b) a named box for a value (c) a phone setting (d) a type of screen
16. 16.💾 Which can hold many values in order? (a) a single number (b) a button (c) a list (d) a switch
17. 17.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) notes to read offline (d) a class leaderboard
18. 18.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
19. 19.💾 What number does this code show?
    let points = 6;
    points = points - 4;
    points = points + 4;
    show(points);
20. 20.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Riya", "Aman"];
    show(friends[2]); (a) Zoya (b) Riya (c) Aman
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Kabir", "Arjun"];
    show(friends[0]); (a) Kabir (b) Arjun (c) Aman
22. 22.💾 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
23. 23.💾 What number does this code show?
    let songs = ["Ocean", "Rain"];
    songs.push("Stars");
    show(songs.length);
24. 24.💾 What number does this code show?
    let songs = ["Ocean", "Rain", "Monsoon"];
    songs.push("Kites");
    songs.push("Stars");
    show(songs.length);
25. 25.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Sports", "Hindi", "Music", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Hindi (c) Sports (d) Music
26. 26.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Meera", "Riya"];
    show(friends[0]); (a) Arjun (b) Meera (c) Riya
27. 27.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Rain", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Kites (c) Rain
28. 28.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud backup (c) a cloud leaderboard (d) a shared chat
29. 29.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Arjun", "Zoya", "Meera", "Aman"];
    show(friends[4]); (a) Arjun (b) Aman (c) Zoya (d) Riya
30. 30.💾 What number does this code show?
    let lives = 3;
    lives = lives - 3;
    lives = lives + 4;
    show(lives);
31. 31.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
32. 32.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
33. 33.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
34. 34.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Ocean", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Monsoon
35. 35.💾 What number does this code show?
    let score = 8;
    score = score - 5;
    score = score + 5;
    show(score);
36. 36.💾 What number does this code show?
    let points = 4;
    points = points - 1;
    points = points + 5;
    show(points);
37. 37.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) a class leaderboard (d) your last game level
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Monsoon", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Ocean (c) Stars
39. 39.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
40. 40.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 0 (d) 2

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