App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 66 · 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 chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
2. 2.💾 What number does this code show?
   let stars = 4;
   stars = stars - 4;
   stars = stars + 5;
   show(stars);
3. 3.💾 pop() takes off the last item. What does this code show?
   let songs = ["Sunrise", "Rain", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Sunrise (b) Rain (c) Kites
4. 4.💾 What number does this code show?
   let friends = ["Meera", "Riya", "Zoya", "Arjun"];
   friends.push("Kabir");
   show(friends.length);
5. 5.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a class leaderboard (c) your last game level (d) notes to read offline
6. 6.💾 Which works with no internet at all? (a) a shared chat (b) a cloud backup (c) data saved on the phone (d) a cloud leaderboard
7. 7.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
8. 8.True or false: your last game level fits saving in the cloud. (a) False (b) True
9. 9.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
10. 10.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
11. 11.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Sunrise", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Sunrise (c) Monsoon
12. 12.True or false: notes to read offline fits saving on the phone. (a) True (b) False
13. 13.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
14. 14.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
15. 15.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Rain", "Kites", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Rain (c) Kites (d) Stars
16. 16.💾 What is a variable? (a) a named box for a value (b) a picture (c) a phone setting (d) a type of screen
17. 17.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Arjun", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Meera (c) Arjun
18. 18.💾 What number does this code show?
    let notes = ["Maths", "Music", "Art", "Hindi"];
    notes.push("Sports");
    show(notes.length);
19. 19.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Meera", "Arjun", "Aman", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Aman (c) Zoya (d) Meera
20. 20.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Zoya", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Riya (c) Zoya (d) Kabir
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Meera", "Riya", "Aman"];
    show(friends[1]); (a) Meera (b) Riya (c) Arjun (d) Aman
22. 22.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a class leaderboard (d) your last game level
23. 23.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the phone is lost (c) you send a message (d) the app is closed
24. 24.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 10 (c) 2 (d) 1
25. 25.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
26. 26.💾 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
27. 27.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
28. 28.Which of these fits saving in the cloud? (a) your last game level (b) a shared to-do list (c) notes to read offline (d) the sound on/off setting
29. 29.💾 What number does this code show?
    let points = 6;
    points = points - 4;
    points = points + 5;
    show(points);
30. 30.💾 What number does this code show?
    let friends = ["Zoya", "Meera", "Arjun"];
    friends.push("Riya");
    friends.push("Aman");
    show(friends.length);
31. 31.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Arjun", "Riya"];
    show(friends[2]); (a) Aman (b) Arjun (c) Riya
32. 32.💾 What number does this code show?
    let notes = ["Music", "Maths"];
    notes.push("Art");
    notes.push("Sports");
    show(notes.length);
33. 33.💾 What number does this code show?
    let score = 5;
    score = score - 5;
    score = score + 3;
    show(score);
34. 34.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
35. 35.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
36. 36.💾 What number does this code show?
    let notes = ["Art", "Music"];
    notes.push("Maths");
    notes.push("Hindi");
    show(notes.length);
37. 37.💾 What number does this code show?
    let coins = 8;
    coins = coins - 4;
    coins = coins + 1;
    show(coins);
38. 38.True or false: photos on two devices fits saving on the phone. (a) False (b) True
39. 39.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Zoya", "Arjun", "Riya"];
    show(friends[1]); (a) Aman (b) Zoya (c) Riya (d) Arjun
40. 40.💾 What number does this code show?
    let songs = ["Sunrise", "Stars", "Monsoon", "Rain"];
    songs.push("Kites");
    show(songs.length);

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