App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 298 · 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.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) a draft you are typing (d) a shared to-do list
2. 2.💾 What does this code show? (Positions start at 0.)
   let songs = ["Monsoon", "Stars", "Sunrise", "Kites"];
   show(songs[2]); (a) Sunrise (b) Stars (c) Kites (d) Monsoon
3. 3.💾 pop() takes off the last item. What does this code show?
   let notes = ["Sports", "Maths", "Science", "Hindi", "Art"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Science (b) Sports (c) Maths (d) Hindi
4. 4.Which of these fits saving on the phone? (a) your last game level (b) chat messages to friends (c) a class leaderboard (d) photos on two devices
5. 5.💾 What number does this code show?
   let points = 9;
   points = points - 5;
   points = points + 5;
   show(points);
6. 6.True or false: your last game level fits saving in the cloud. (a) True (b) False
7. 7.💾 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
8. 8.💾 What number does this code show?
   let songs = ["Rain", "Monsoon", "Kites", "Stars"];
   songs.push("Ocean");
   show(songs.length);
9. 9.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
10. 10.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Ocean", "Kites", "Rain", "Monsoon"];
    show(songs[1]); (a) Ocean (b) Rain (c) Sunrise (d) Kites
11. 11.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
12. 12.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
13. 13.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Maths", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Maths (d) Sports
14. 14.Which of these fits saving on the phone? (a) notes to read offline (b) chat messages to friends (c) photos on two devices (d) a shared to-do list
15. 15.💾 What number does this code show?
    let notes = ["Maths", "Art"];
    notes.push("Hindi");
    show(notes.length);
16. 16.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
17. 17.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
18. 18.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) you send a message (d) the phone is lost
19. 19.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
20. 20.Which of these fits saving on the phone? (a) photos on two devices (b) a draft you are typing (c) a shared to-do list (d) chat messages to friends
21. 21.💾 Which can hold many values in order? (a) a single number (b) a switch (c) a button (d) a list
22. 22.💾 What number does this code show?
    let songs = ["Stars", "Monsoon", "Rain", "Sunrise"];
    songs.push("Kites");
    songs.push("Ocean");
    show(songs.length);
23. 23.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
24. 24.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
25. 25.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
26. 26.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 4;
    show(coins);
27. 27.💾 What number does this code show?
    let notes = ["Music", "Maths", "Sports"];
    notes.push("Science");
    notes.push("Hindi");
    show(notes.length);
28. 28.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 1;
    show(score);
29. 29.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Kabir", "Meera", "Aman", "Zoya"];
    show(friends[1]); (a) Aman (b) Arjun (c) Kabir (d) Meera
30. 30.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 0 (d) 1
31. 31.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) skip the internet (d) use it on any device
32. 32.💾 What number does this code show?
    let score = 4;
    score = score - 2;
    score = score + 3;
    show(score);
33. 33.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
34. 34.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Ocean", "Rain", "Monsoon", "Stars"];
    show(songs[4]); (a) Stars (b) Kites (c) Ocean (d) Rain
35. 35.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Zoya", "Riya"];
    show(friends[1]); (a) Riya (b) Meera (c) Zoya
36. 36.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Sunrise", "Kites", "Monsoon", "Rain"];
    show(songs[4]); (a) Sunrise (b) Rain (c) Stars (d) Kites
37. 37.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) a class leaderboard (d) the sound on/off setting
38. 38.💾 What number does this code show?
    let songs = ["Sunrise", "Kites"];
    songs.push("Ocean");
    show(songs.length);
39. 39.💾 What number does this code show?
    let notes = ["Sports", "Maths", "Science"];
    notes.push("Art");
    show(notes.length);
40. 40.💾 What number does this code show?
    let score = 9;
    score = score - 7;
    score = score + 4;
    show(score);

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