App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 544 · 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 number does this code show?
   let songs = ["Monsoon", "Sunrise", "Kites"];
   songs.push("Rain");
   show(songs.length);
2. 2.Which of these fits saving on the phone? (a) a class leaderboard (b) your last game level (c) photos on two devices (d) chat messages to friends
3. 3.💾 pop() takes off the last item. What does this code show?
   let notes = ["Sports", "Music", "Maths"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Music
4. 4.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Riya", "Arjun", "Meera"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Arjun (d) Meera
5. 5.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.💾 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
7. 7.💾 What does this code show? (Positions start at 0.)
   let songs = ["Rain", "Monsoon", "Ocean"];
   show(songs[0]); (a) Ocean (b) Rain (c) Monsoon
8. 8.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 2 (c) 1 (d) 0
10. 10.Which of these fits saving on the phone? (a) the sound on/off setting (b) a class leaderboard (c) a shared to-do list (d) chat messages to friends
11. 11.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
12. 12.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the screen turns off (d) the phone is lost
13. 13.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
14. 14.True or false: photos on two devices fits saving on the phone. (a) False (b) True
15. 15.💾 What number does this code show?
    let score = 7;
    score = score - 4;
    score = score + 4;
    show(score);
16. 16.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Stars", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Rain (c) Stars
17. 17.💾 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
18. 18.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) the sound on/off setting (d) a class leaderboard
19. 19.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Art", "Sports"];
    show(notes[3]); (a) Maths (b) Art (c) Music (d) Sports
20. 20.💾 What number does this code show?
    let score = 5;
    score = score - 5;
    score = score + 3;
    show(score);
21. 21.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Maths"];
    show(notes[2]); (a) Music (b) Art (c) Maths
22. 22.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
23. 23.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
24. 24.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) never need a password (d) use it on any device
25. 25.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Hindi (c) Sports
26. 26.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Meera", "Aman", "Kabir"];
    show(friends[0]); (a) Riya (b) Kabir (c) Aman (d) Meera
27. 27.💾 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
28. 28.💾 What number does this code show?
    let friends = ["Arjun", "Zoya", "Kabir", "Aman"];
    friends.push("Meera");
    show(friends.length);
29. 29.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
30. 30.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
31. 31.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Aman"];
    show(friends[0]); (a) Aman (b) Kabir (c) Meera
32. 32.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) the sound on/off setting (d) a shared to-do list
33. 33.Which of these fits saving in the cloud? (a) photos on two devices (b) notes to read offline (c) your last game level (d) the sound on/off setting
34. 34.💾 Which works with no internet at all? (a) a cloud backup (b) a shared chat (c) data saved on the phone (d) a cloud leaderboard
35. 35.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a shared to-do list (d) notes to read offline
36. 36.💾 What is a variable? (a) a type of screen (b) a picture (c) a named box for a value (d) a phone setting
37. 37.💾 What number does this code show?
    let songs = ["Stars", "Ocean"];
    songs.push("Kites");
    show(songs.length);
38. 38.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Kabir", "Zoya"];
    show(friends[2]); (a) Kabir (b) Arjun (c) Zoya
39. 39.True or false: notes to read offline fits saving on the phone. (a) False (b) True
40. 40.💾 What number does this code show?
    let songs = ["Kites", "Sunrise"];
    songs.push("Rain");
    show(songs.length);

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