App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 244 · 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.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
2. 2.💾 pop() takes off the last item. What does this code show?
   let notes = ["Science", "Hindi", "Maths"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Maths (b) Hindi (c) Science
3. 3.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.True or false: photos on two devices fits saving on the phone. (a) False (b) True
5. 5.💾 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
6. 6.💾 What number does this code show?
   let friends = ["Kabir", "Zoya"];
   friends.push("Riya");
   friends.push("Aman");
   show(friends.length);
7. 7.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
8. 8.💾 pop() takes off the last item. What does this code show?
   let songs = ["Stars", "Ocean", "Sunrise"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Ocean (b) Sunrise (c) Stars
9. 9.💾 What number does this code show?
   let songs = ["Sunrise", "Stars", "Kites"];
   songs.push("Rain");
   songs.push("Monsoon");
   show(songs.length);
10. 10.💾 What number does this code show?
    let friends = ["Aman", "Kabir", "Meera", "Riya"];
    friends.push("Zoya");
    show(friends.length);
11. 11.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
12. 12.💾 What number does this code show?
    let notes = ["Hindi", "Sports"];
    notes.push("Maths");
    notes.push("Music");
    show(notes.length);
13. 13.💾 What number does this code show?
    let notes = ["Maths", "Science"];
    notes.push("Art");
    show(notes.length);
14. 14.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
15. 15.💾 What number does this code show?
    let friends = ["Arjun", "Aman"];
    friends.push("Kabir");
    friends.push("Zoya");
    show(friends.length);
16. 16.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
17. 17.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Hindi", "Maths"];
    show(notes[0]); (a) Art (b) Hindi (c) Science (d) Maths
18. 18.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Monsoon", "Kites", "Stars", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Stars (d) Monsoon
19. 19.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Meera", "Arjun", "Zoya", "Aman"];
    show(friends[4]); (a) Arjun (b) Riya (c) Aman (d) Meera
20. 20.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
21. 21.💾 What number does this code show?
    let friends = ["Kabir", "Riya", "Arjun", "Meera"];
    friends.push("Zoya");
    show(friends.length);
22. 22.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
23. 23.Which of these fits saving on the phone? (a) your last game level (b) a shared to-do list (c) a class leaderboard (d) chat messages to friends
24. 24.Which of these fits saving in the cloud? (a) chat messages to friends (b) the sound on/off setting (c) notes to read offline (d) a draft you are typing
25. 25.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) a class leaderboard (d) notes to read offline
26. 26.Which of these fits saving in the cloud? (a) your last game level (b) a class leaderboard (c) the sound on/off setting (d) a draft you are typing
27. 27.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Music", "Maths"];
    show(notes[0]); (a) Music (b) Maths (c) Hindi
28. 28.💾 What number does this code show?
    let coins = 4;
    coins = coins - 2;
    coins = coins + 4;
    show(coins);
29. 29.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
30. 30.💾 What number does this code show?
    let songs = ["Ocean", "Monsoon", "Stars"];
    songs.push("Kites");
    songs.push("Rain");
    show(songs.length);
31. 31.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
32. 32.💾 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
33. 33.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
34. 34.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
35. 35.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Meera", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Riya (c) Kabir
36. 36.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
37. 37.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) in the cloud (b) on the phone
38. 38.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Art", "Science"];
    show(notes[0]); (a) Art (b) Science (c) Sports (d) Maths
39. 39.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) never need a password (c) shrink the app (d) use it on any device
40. 40.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 0 (d) 2

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