App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 859 · 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 does this code show? (Positions start at 0.)
   let notes = ["Art", "Music", "Maths"];
   show(notes[1]); (a) Maths (b) Art (c) Music
2. 2.💾 pop() takes off the last item. What does this code show?
   let friends = ["Riya", "Zoya", "Meera", "Aman"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Meera (b) Zoya (c) Riya (d) Aman
3. 3.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Art", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Art
4. 4.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
5. 5.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
6. 6.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 2 (d) 0
7. 7.💾 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
8. 8.💾 What number does this code show?
   let coins = 9;
   coins = coins - 8;
   coins = coins + 5;
   show(coins);
9. 9.💾 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
10. 10.Which of these fits saving in the cloud? (a) notes to read offline (b) chat messages to friends (c) a draft you are typing (d) the sound on/off setting
11. 11.💾 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
12. 12.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
13. 13.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the app is closed (c) you send a message (d) the phone is lost
14. 14.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Meera", "Zoya", "Riya"];
    show(friends[2]); (a) Riya (b) Zoya (c) Meera (d) Aman
15. 15.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
16. 16.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
17. 17.💾 What number does this code show?
    let notes = ["Maths", "Hindi", "Music"];
    notes.push("Art");
    show(notes.length);
18. 18.💾 What is a variable? (a) a type of screen (b) a named box for a value (c) a picture (d) a phone setting
19. 19.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Sports", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Sports
20. 20.Which of these fits saving on the phone? (a) chat messages to friends (b) your last game level (c) a shared to-do list (d) a class leaderboard
21. 21.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
22. 22.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Meera", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Riya (c) Arjun
23. 23.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) shrink the app (c) never need a password (d) skip the internet
24. 24.💾 What number does this code show?
    let songs = ["Kites", "Monsoon"];
    songs.push("Ocean");
    songs.push("Stars");
    show(songs.length);
25. 25.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
26. 26.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) a shared to-do list (d) the sound on/off setting
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.Which of these fits saving in the cloud? (a) notes to read offline (b) photos on two devices (c) your last game level (d) the sound on/off setting
29. 29.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Zoya", "Arjun", "Meera", "Kabir"];
    show(friends[4]); (a) Zoya (b) Kabir (c) Riya (d) Arjun
30. 30.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) a class leaderboard
31. 31.💾 What number does this code show?
    let notes = ["Art", "Maths"];
    notes.push("Music");
    notes.push("Hindi");
    show(notes.length);
32. 32.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Music", "Science"];
    show(notes[1]); (a) Music (b) Science (c) Hindi
33. 33.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a draft you are typing (d) a shared to-do list
34. 34.💾 What number does this code show?
    let stars = 8;
    stars = stars - 5;
    stars = stars + 3;
    show(stars);
35. 35.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) a shared to-do list (d) your last game level
36. 36.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Sunrise", "Kites", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Kites (c) Sunrise (d) Rain
37. 37.💾 What number does this code show?
    let points = 7;
    points = points - 2;
    points = points + 4;
    show(points);
38. 38.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
39. 39.💾 What number does this code show?
    let stars = 4;
    stars = stars - 2;
    stars = stars + 1;
    show(stars);
40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Sunrise", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Sunrise (c) Ocean

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