App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 255 · 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.💾 pop() takes off the last item. What does this code show?
   let songs = ["Kites", "Monsoon", "Stars", "Sunrise"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Monsoon (b) Kites (c) Sunrise (d) Stars
2. 2.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) a shared to-do list (d) chat messages to friends
3. 3.💾 What does this code show? (Positions start at 0.)
   let friends = ["Riya", "Zoya", "Arjun"];
   show(friends[0]); (a) Zoya (b) Arjun (c) Riya
4. 4.💾 What number does this code show?
   let friends = ["Aman", "Riya", "Arjun", "Zoya"];
   friends.push("Meera");
   friends.push("Kabir");
   show(friends.length);
5. 5.💾 What number does this code show?
   let score = 5;
   score = score - 5;
   score = score + 2;
   show(score);
6. 6.💾 What number does this code show?
   let score = 4;
   score = score - 2;
   score = score + 5;
   show(score);
7. 7.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
8. 8.💾 What number does this code show?
   let notes = ["Sports", "Science", "Maths"];
   notes.push("Hindi");
   notes.push("Art");
   show(notes.length);
9. 9.💾 What is a variable? (a) a picture (b) a named box for a value (c) a phone setting (d) a type of screen
10. 10.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
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.💾 What number does this code show?
    let score = 4;
    score = score - 2;
    score = score + 4;
    show(score);
13. 13.💾 What number does this code show?
    let friends = ["Kabir", "Meera"];
    friends.push("Zoya");
    friends.push("Arjun");
    show(friends.length);
14. 14.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Arjun", "Aman", "Riya"];
    show(friends[3]); (a) Aman (b) Meera (c) Riya (d) Arjun
15. 15.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) a shared to-do list (d) your last game level
16. 16.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 1 (d) 10
17. 17.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
18. 18.💾 What number does this code show?
    let songs = ["Kites", "Rain", "Ocean"];
    songs.push("Stars");
    show(songs.length);
19. 19.💾 What number does this code show?
    let score = 7;
    score = score - 1;
    score = score + 1;
    show(score);
20. 20.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
21. 21.💾 Which works with no internet at all? (a) a cloud backup (b) a shared chat (c) a cloud leaderboard (d) data saved on the phone
22. 22.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
23. 23.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) chat messages to friends (d) the sound on/off setting
24. 24.Which of these fits saving in the cloud? (a) chat messages to friends (b) a draft you are typing (c) the sound on/off setting (d) your last game level
25. 25.Which of these fits saving on the phone? (a) a draft you are typing (b) photos on two devices (c) a class leaderboard (d) a shared to-do list
26. 26.💾 What number does this code show?
    let notes = ["Hindi", "Sports", "Music"];
    notes.push("Maths");
    show(notes.length);
27. 27.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) in the cloud (b) on the phone
28. 28.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Ocean (c) Rain
29. 29.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
30. 30.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
31. 31.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a shared to-do list (d) a draft you are typing
32. 32.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Science", "Maths", "Art", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Art (c) Sports (d) Maths
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Science", "Sports", "Hindi"];
    show(notes[0]); (a) Maths (b) Sports (c) Science (d) Art
34. 34.💾 Which can hold many values in order? (a) a button (b) a list (c) a single number (d) a switch
35. 35.💾 What number does this code show?
    let score = 5;
    score = score - 1;
    score = score + 3;
    show(score);
36. 36.💾 What number does this code show?
    let stars = 9;
    stars = stars - 7;
    stars = stars + 3;
    show(stars);
37. 37.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
38. 38.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
39. 39.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Ocean", "Stars"];
    show(songs[3]); (a) Stars (b) Ocean (c) Rain (d) Monsoon
40. 40.💾 What number does this code show?
    let friends = ["Aman", "Zoya", "Riya", "Kabir"];
    friends.push("Meera");
    show(friends.length);

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