App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 165 · 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.💾 Which works with no internet at all? (a) a shared chat (b) a cloud backup (c) a cloud leaderboard (d) data saved on the phone
2. 2.Which of these fits saving in the cloud? (a) your last game level (b) a shared to-do list (c) the sound on/off setting (d) notes to read offline
3. 3.💾 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
4. 4.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) your last game level (d) photos on two devices
5. 5.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Art", "Sports", "Hindi", "Music"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Hindi (c) Maths (d) Art
6. 6.💾 What number does this code show?
   let coins = 5;
   coins = coins - 2;
   coins = coins + 4;
   show(coins);
7. 7.💾 What number does this code show?
   let songs = ["Stars", "Sunrise"];
   songs.push("Rain");
   show(songs.length);
8. 8.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
9. 9.💾 What is a variable? (a) a phone setting (b) a picture (c) a type of screen (d) a named box for a value
10. 10.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Sports", "Hindi", "Science"];
    show(notes[1]); (a) Sports (b) Hindi (c) Science (d) Art
11. 11.💾 What number does this code show?
    let notes = ["Music", "Science", "Maths", "Art"];
    notes.push("Sports");
    notes.push("Hindi");
    show(notes.length);
12. 12.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
13. 13.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 10 (d) 1
14. 14.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a draft you are typing (d) photos on two devices
15. 15.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
16. 16.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Aman", "Arjun", "Zoya"];
    show(friends[3]); (a) Aman (b) Kabir (c) Arjun (d) Zoya
17. 17.💾 What number does this code show?
    let lives = 4;
    lives = lives - 4;
    lives = lives + 5;
    show(lives);
18. 18.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
19. 19.💾 What number does this code show?
    let stars = 4;
    stars = stars - 2;
    stars = stars + 4;
    show(stars);
20. 20.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Rain", "Monsoon", "Stars"];
    show(songs[0]); (a) Rain (b) Monsoon (c) Ocean (d) Stars
21. 21.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) skip the internet (d) use it on any device
22. 22.💾 What number does this code show?
    let friends = ["Meera", "Arjun", "Riya", "Kabir"];
    friends.push("Aman");
    friends.push("Zoya");
    show(friends.length);
23. 23.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
24. 24.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) you send a message (d) the phone is lost
25. 25.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
26. 26.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Zoya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Aman (c) Meera
27. 27.💾 What number does this code show?
    let coins = 9;
    coins = coins - 6;
    coins = coins + 3;
    show(coins);
28. 28.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
29. 29.💾 What number does this code show?
    let points = 4;
    points = points - 4;
    points = points + 5;
    show(points);
30. 30.💾 What number does this code show?
    let score = 4;
    score = score - 4;
    score = score + 5;
    show(score);
31. 31.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a shared to-do list (d) the sound on/off setting
32. 32.💾 What number does this code show?
    let friends = ["Riya", "Arjun"];
    friends.push("Meera");
    show(friends.length);
33. 33.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Aman", "Riya", "Meera"];
    show(friends[2]); (a) Meera (b) Aman (c) Riya (d) Arjun
34. 34.💾 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
35. 35.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
36. 36.💾 What number does this code show?
    let songs = ["Ocean", "Stars", "Sunrise"];
    songs.push("Rain");
    songs.push("Monsoon");
    show(songs.length);
37. 37.💾 What number does this code show?
    let notes = ["Sports", "Hindi"];
    notes.push("Maths");
    show(notes.length);
38. 38.💾 What number does this code show?
    let notes = ["Hindi", "Maths", "Art"];
    notes.push("Science");
    notes.push("Music");
    show(notes.length);
39. 39.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Sports", "Hindi", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Art (c) Sports (d) Hindi
40. 40.💾 What number does this code show?
    let songs = ["Ocean", "Kites", "Rain", "Sunrise"];
    songs.push("Stars");
    songs.push("Monsoon");
    show(songs.length);

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