App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 349 · 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 named box for a value (b) a phone setting (c) a picture (d) a type of screen
2. 2.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
3. 3.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
4. 4.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
5. 5.💾 What number does this code show?
   let songs = ["Kites", "Rain", "Monsoon"];
   songs.push("Sunrise");
   songs.push("Stars");
   show(songs.length);
6. 6.💾 What number does this code show?
   let notes = ["Maths", "Art", "Hindi"];
   notes.push("Sports");
   notes.push("Music");
   show(notes.length);
7. 7.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
8. 8.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) your last game level (d) photos on two devices
9. 9.💾 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
10. 10.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Art", "Science", "Hindi", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Maths (d) Science
11. 11.Which of these fits saving on the phone? (a) a shared to-do list (b) notes to read offline (c) chat messages to friends (d) photos on two devices
12. 12.True or false: your last game level fits saving on the phone. (a) False (b) True
13. 13.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 0 (d) 2
14. 14.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Monsoon", "Sunrise", "Rain"];
    show(songs[1]); (a) Rain (b) Sunrise (c) Monsoon (d) Stars
15. 15.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) notes to read offline (d) a shared to-do list
16. 16.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Sports", "Hindi"];
    show(notes[1]); (a) Hindi (b) Art (c) Sports
17. 17.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the phone is lost (c) the screen turns off (d) you send a message
18. 18.💾 Which can hold many values in order? (a) a list (b) a button (c) a switch (d) a single number
19. 19.Which of these fits saving in the cloud? (a) a class leaderboard (b) a draft you are typing (c) your last game level (d) notes to read offline
20. 20.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Maths", "Science"];
    show(notes[2]); (a) Hindi (b) Maths (c) Science
21. 21.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Science", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Science (c) Sports
22. 22.💾 What number does this code show?
    let points = 9;
    points = points - 7;
    points = points + 3;
    show(points);
23. 23.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
24. 24.💾 What number does this code show?
    let songs = ["Ocean", "Rain"];
    songs.push("Kites");
    songs.push("Stars");
    show(songs.length);
25. 25.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Meera", "Aman"];
    show(friends[0]); (a) Meera (b) Arjun (c) Aman
26. 26.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Rain", "Ocean", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Ocean (c) Monsoon (d) Stars
27. 27.💾 What number does this code show?
    let notes = ["Hindi", "Music"];
    notes.push("Maths");
    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) on the phone (b) in the cloud
29. 29.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
30. 30.💾 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
31. 31.Which of these fits saving in the cloud? (a) chat messages to friends (b) notes to read offline (c) the sound on/off setting (d) a draft you are typing
32. 32.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Science", "Sports", "Music", "Hindi"];
    show(notes[1]); (a) Music (b) Science (c) Maths (d) Sports
34. 34.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Maths", "Hindi", "Sports", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Maths (c) Sports (d) Music
35. 35.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Arjun", "Zoya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Meera (c) Zoya (d) Aman
36. 36.True or false: your last game level fits saving in the cloud. (a) False (b) True
37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Art", "Hindi", "Science"];
    show(notes[3]); (a) Art (b) Music (c) Maths (d) Hindi
38. 38.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) chat messages to friends (d) the sound on/off setting
39. 39.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
40. 40.💾 What number does this code show?
    let songs = ["Kites", "Sunrise"];
    songs.push("Rain");
    songs.push("Stars");
    show(songs.length);

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