App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 717 · 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 stars = 7;
   stars = stars - 6;
   stars = stars + 4;
   show(stars);
2. 2.True or false: your last game level fits saving in the cloud. (a) False (b) True
3. 3.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) notes to read offline (d) photos on two devices
4. 4.💾 What number does this code show?
   let notes = ["Maths", "Science", "Music"];
   notes.push("Sports");
   show(notes.length);
5. 5.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) a shared to-do list (d) the sound on/off setting
6. 6.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the phone is lost (d) the app is closed
7. 7.💾 Which can hold many values in order? (a) a list (b) a single number (c) a button (d) a switch
8. 8.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
9. 9.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a shared chat (c) data saved on the phone (d) a cloud backup
10. 10.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Aman", "Zoya", "Arjun", "Meera"];
    show(friends[3]); (a) Arjun (b) Riya (c) Zoya (d) Aman
11. 11.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Rain", "Kites", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Monsoon (c) Kites (d) Stars
12. 12.💾 What number does this code show?
    let points = 5;
    points = points - 4;
    points = points + 1;
    show(points);
13. 13.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Meera", "Aman", "Kabir"];
    show(friends[0]); (a) Riya (b) Meera (c) Kabir (d) Aman
14. 14.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Science", "Hindi", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Hindi (d) Science
15. 15.💾 What number does this code show?
    let points = 9;
    points = points - 3;
    points = points + 2;
    show(points);
16. 16.True or false: your last game level fits saving on the phone. (a) False (b) True
17. 17.💾 What number does this code show?
    let notes = ["Sports", "Maths", "Art", "Hindi"];
    notes.push("Music");
    show(notes.length);
18. 18.Which of these fits saving on the phone? (a) a class leaderboard (b) your last game level (c) chat messages to friends (d) a shared to-do list
19. 19.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
20. 20.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
21. 21.💾 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
22. 22.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
23. 23.💾 What number does this code show?
    let notes = ["Sports", "Art", "Maths"];
    notes.push("Music");
    notes.push("Hindi");
    show(notes.length);
24. 24.💾 What number does this code show?
    let notes = ["Maths", "Art", "Hindi", "Music"];
    notes.push("Sports");
    notes.push("Science");
    show(notes.length);
25. 25.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Maths", "Sports"];
    show(notes[0]); (a) Music (b) Maths (c) Art (d) Sports
26. 26.💾 What number does this code show?
    let notes = ["Hindi", "Sports", "Art", "Science"];
    notes.push("Maths");
    show(notes.length);
27. 27.💾 What number does this code show?
    let songs = ["Stars", "Rain"];
    songs.push("Ocean");
    show(songs.length);
28. 28.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Zoya", "Riya", "Kabir", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Riya (c) Aman (d) Kabir
29. 29.💾 What number does this code show?
    let score = 6;
    score = score - 2;
    score = score + 3;
    show(score);
30. 30.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Arjun", "Zoya"];
    show(friends[0]); (a) Zoya (b) Meera (c) Arjun
31. 31.Which of these fits saving on the phone? (a) the sound on/off setting (b) photos on two devices (c) a shared to-do list (d) a class leaderboard
32. 32.💾 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
33. 33.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
34. 34.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
35. 35.💾 What number does this code show?
    let songs = ["Stars", "Rain"];
    songs.push("Ocean");
    songs.push("Monsoon");
    show(songs.length);
36. 36.💾 What number does this code show?
    let friends = ["Riya", "Meera", "Arjun", "Kabir"];
    friends.push("Aman");
    friends.push("Zoya");
    show(friends.length);
37. 37.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
38. 38.💾 What number does this code show?
    let coins = 7;
    coins = coins - 2;
    coins = coins + 5;
    show(coins);
39. 39.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 1 (d) 10
40. 40.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone

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