App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 310 · 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 coins = 3;
   coins = coins - 1;
   coins = coins + 1;
   show(coins);
2. 2.💾 What number does this code show?
   let points = 8;
   points = points - 7;
   points = points + 4;
   show(points);
3. 3.💾 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
4. 4.💾 What is a variable? (a) a named box for a value (b) a type of screen (c) a picture (d) a phone setting
5. 5.💾 What number does this code show?
   let notes = ["Maths", "Science", "Hindi"];
   notes.push("Sports");
   show(notes.length);
6. 6.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.💾 What number does this code show?
   let friends = ["Zoya", "Meera"];
   friends.push("Kabir");
   friends.push("Arjun");
   show(friends.length);
8. 8.💾 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
9. 9.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.💾 What number does this code show?
    let notes = ["Maths", "Sports", "Music"];
    notes.push("Hindi");
    notes.push("Art");
    show(notes.length);
11. 11.Which of these fits saving on the phone? (a) a shared to-do list (b) the sound on/off setting (c) a class leaderboard (d) photos on two devices
12. 12.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Aman", "Arjun", "Zoya"];
    show(friends[0]); (a) Riya (b) Arjun (c) Zoya (d) Aman
13. 13.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
14. 14.💾 What number does this code show?
    let songs = ["Monsoon", "Kites", "Ocean", "Sunrise"];
    songs.push("Rain");
    songs.push("Stars");
    show(songs.length);
15. 15.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
16. 16.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Hindi", "Science", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Science (c) Hindi (d) Sports
17. 17.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
18. 18.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 2 (d) 0
19. 19.True or false: notes to read offline fits saving on the phone. (a) False (b) True
20. 20.💾 What number does this code show?
    let coins = 9;
    coins = coins - 9;
    coins = coins + 2;
    show(coins);
21. 21.💾 What number does this code show?
    let notes = ["Sports", "Science"];
    notes.push("Music");
    notes.push("Art");
    show(notes.length);
22. 22.💾 What number does this code show?
    let notes = ["Art", "Maths"];
    notes.push("Music");
    show(notes.length);
23. 23.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Hindi", "Music"];
    show(notes[1]); (a) Music (b) Hindi (c) Sports
24. 24.💾 What number does this code show?
    let coins = 5;
    coins = coins - 4;
    coins = coins + 1;
    show(coins);
25. 25.Which of these fits saving in the cloud? (a) your last game level (b) a class leaderboard (c) the sound on/off setting (d) a draft you are typing
26. 26.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Sports", "Maths", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Art (c) Sports (d) Maths
27. 27.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
28. 28.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Kabir", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Meera (c) Kabir
29. 29.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a shared to-do list (d) a draft you are typing
30. 30.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) data saved on the phone (d) a shared chat
31. 31.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
32. 32.💾 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
33. 33.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
34. 34.💾 What number does this code show?
    let notes = ["Music", "Art"];
    notes.push("Maths");
    show(notes.length);
35. 35.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) never need a password (c) shrink the app (d) use it on any device
36. 36.💾 What number does this code show?
    let songs = ["Ocean", "Kites", "Rain", "Sunrise"];
    songs.push("Stars");
    show(songs.length);
37. 37.💾 What number does this code show?
    let points = 7;
    points = points - 5;
    points = points + 3;
    show(points);
38. 38.💾 What number does this code show?
    let songs = ["Rain", "Sunrise", "Stars", "Monsoon"];
    songs.push("Ocean");
    show(songs.length);
39. 39.True or false: your last game level fits saving in the cloud. (a) True (b) False
40. 40.💾 What number does this code show?
    let songs = ["Monsoon", "Ocean", "Rain"];
    songs.push("Kites");
    songs.push("Stars");
    show(songs.length);

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