App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 204 · 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 songs = ["Stars", "Monsoon", "Rain"];
   show(songs[1]); (a) Stars (b) Rain (c) Monsoon
2. 2.True or false: notes to read offline fits saving on the phone. (a) False (b) True
3. 3.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.💾 Which can hold many values in order? (a) a button (b) a list (c) a switch (d) a single number
5. 5.Which of these fits saving on the phone? (a) the sound on/off setting (b) photos on two devices (c) chat messages to friends (d) a shared to-do list
6. 6.Which of these fits saving on the phone? (a) your last game level (b) a class leaderboard (c) chat messages to friends (d) photos on two devices
7. 7.💾 What does this code show? (Positions start at 0.)
   let notes = ["Sports", "Maths", "Hindi"];
   show(notes[2]); (a) Sports (b) Maths (c) Hindi
8. 8.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Science", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Science
10. 10.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Maths", "Science", "Hindi", "Music"];
    show(notes[4]); (a) Maths (b) Music (c) Sports (d) Science
11. 11.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) the phone is lost (d) you send a message
12. 12.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Riya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Riya (c) Kabir
13. 13.True or false: your last game level fits saving in the cloud. (a) True (b) False
14. 14.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Monsoon", "Sunrise", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Monsoon (c) Stars (d) Rain
15. 15.💾 Which works with no internet at all? (a) a cloud leaderboard (b) data saved on the phone (c) a cloud backup (d) a shared chat
16. 16.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Kites", "Stars", "Ocean", "Monsoon"];
    show(songs[4]); (a) Monsoon (b) Kites (c) Sunrise (d) Stars
17. 17.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
18. 18.💾 What number does this code show?
    let lives = 6;
    lives = lives - 3;
    lives = lives + 4;
    show(lives);
19. 19.💾 What number does this code show?
    let songs = ["Rain", "Sunrise", "Kites"];
    songs.push("Stars");
    songs.push("Ocean");
    show(songs.length);
20. 20.💾 What number does this code show?
    let lives = 3;
    lives = lives - 2;
    lives = lives + 1;
    show(lives);
21. 21.💾 What number does this code show?
    let stars = 4;
    stars = stars - 4;
    stars = stars + 5;
    show(stars);
22. 22.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Riya", "Kabir", "Zoya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Riya (c) Kabir (d) Zoya
23. 23.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) a shared to-do list (d) notes to read offline
24. 24.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 0 (d) 10
25. 25.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
26. 26.💾 What is a variable? (a) a type of screen (b) a phone setting (c) a named box for a value (d) a picture
27. 27.💾 What number does this code show?
    let songs = ["Ocean", "Monsoon", "Rain", "Stars"];
    songs.push("Kites");
    songs.push("Sunrise");
    show(songs.length);
28. 28.💾 What number does this code show?
    let songs = ["Monsoon", "Rain"];
    songs.push("Stars");
    show(songs.length);
29. 29.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
30. 30.💾 What number does this code show?
    let score = 6;
    score = score - 4;
    score = score + 1;
    show(score);
31. 31.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
32. 32.Which of these fits saving on the phone? (a) a class leaderboard (b) a shared to-do list (c) notes to read offline (d) photos on two devices
33. 33.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Aman", "Riya"];
    show(friends[0]); (a) Riya (b) Aman (c) Arjun
34. 34.💾 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
35. 35.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Meera", "Arjun", "Riya", "Zoya"];
    show(friends[0]); (a) Riya (b) Arjun (c) Meera (d) Aman
36. 36.💾 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
37. 37.💾 What number does this code show?
    let songs = ["Stars", "Kites", "Rain"];
    songs.push("Monsoon");
    show(songs.length);
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Kites", "Rain", "Sunrise", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Rain (c) Ocean (d) Kites
39. 39.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
40. 40.💾 What number does this code show?
    let friends = ["Arjun", "Kabir"];
    friends.push("Meera");
    show(friends.length);

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