App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 887 · 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 is a variable? (a) a phone setting (b) a picture (c) a type of screen (d) a named box for a value
2. 2.💾 What number does this code show?
   let notes = ["Hindi", "Maths", "Music", "Sports"];
   notes.push("Science");
   notes.push("Art");
   show(notes.length);
3. 3.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
4. 4.💾 What does this code show? (Positions start at 0.)
   let notes = ["Music", "Hindi", "Maths"];
   show(notes[2]); (a) Hindi (b) Music (c) Maths
5. 5.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
6. 6.💾 What does this code show? (Positions start at 0.)
   let songs = ["Kites", "Monsoon", "Sunrise"];
   show(songs[1]); (a) Sunrise (b) Monsoon (c) Kites
7. 7.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
8. 8.True or false: notes to read offline fits saving on the phone. (a) False (b) True
9. 9.Which of these fits saving on the phone? (a) your last game level (b) photos on two devices (c) chat messages to friends (d) a class leaderboard
10. 10.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Stars", "Kites"];
    show(songs[1]); (a) Rain (b) Stars (c) Kites
11. 11.💾 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
12. 12.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
13. 13.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 2 (d) 10
14. 14.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
15. 15.💾 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) Art (b) Maths (c) Science (d) Music
16. 16.💾 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
17. 17.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
18. 18.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
19. 19.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Kites", "Monsoon", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Rain (c) Kites (d) Sunrise
20. 20.💾 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
21. 21.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) photos on two devices
22. 22.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Art", "Science", "Music", "Sports"];
    show(notes[1]); (a) Art (b) Science (c) Music (d) Hindi
23. 23.💾 What number does this code show?
    let songs = ["Stars", "Monsoon", "Kites", "Rain"];
    songs.push("Sunrise");
    show(songs.length);
24. 24.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
25. 25.Which of these fits saving in the cloud? (a) a class leaderboard (b) your last game level (c) a draft you are typing (d) notes to read offline
26. 26.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) notes to read offline (d) photos on two devices
27. 27.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Kites", "Rain", "Sunrise", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Rain (d) Monsoon
28. 28.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Stars", "Rain", "Ocean", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Sunrise (d) Stars
29. 29.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Ocean", "Monsoon", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Sunrise (c) Rain (d) Ocean
30. 30.True or false: your last game level fits saving in the cloud. (a) True (b) False
31. 31.Which of these fits saving in the cloud? (a) chat messages to friends (b) your last game level (c) the sound on/off setting (d) a draft you are typing
32. 32.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the app is closed (c) the phone is lost (d) you send a message
33. 33.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
34. 34.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Riya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Meera (c) Aman
35. 35.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Science", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Science (c) Hindi
36. 36.💾 What number does this code show?
    let songs = ["Monsoon", "Ocean", "Stars", "Rain"];
    songs.push("Sunrise");
    songs.push("Kites");
    show(songs.length);
37. 37.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Sunrise", "Monsoon"];
    show(songs[0]); (a) Sunrise (b) Monsoon (c) Stars
38. 38.💾 What number does this code show?
    let lives = 6;
    lives = lives - 1;
    lives = lives + 3;
    show(lives);
39. 39.💾 Which can hold many values in order? (a) a button (b) a switch (c) a list (d) a single number
40. 40.💾 What number does this code show?
    let notes = ["Maths", "Music"];
    notes.push("Hindi");
    show(notes.length);

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