App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 309 · 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.💾 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
2. 2.Which of these fits saving on the phone? (a) a shared to-do list (b) a draft you are typing (c) photos on two devices (d) chat messages to friends
3. 3.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
4. 4.💾 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
5. 5.💾 What number does this code show?
   let notes = ["Maths", "Science"];
   notes.push("Art");
   notes.push("Sports");
   show(notes.length);
6. 6.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
7. 7.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the screen turns off (c) the app is closed (d) you send a message
8. 8.Which of these fits saving in the cloud? (a) the sound on/off setting (b) chat messages to friends (c) a draft you are typing (d) your last game level
9. 9.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a named box for a value (d) a picture
10. 10.💾 What number does this code show?
    let notes = ["Maths", "Sports", "Hindi"];
    notes.push("Music");
    show(notes.length);
11. 11.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) use it on any device (d) skip the internet
12. 12.💾 What number does this code show?
    let coins = 6;
    coins = coins - 5;
    coins = coins + 1;
    show(coins);
13. 13.Which of these fits saving on the phone? (a) photos on two devices (b) the sound on/off setting (c) a shared to-do list (d) a class leaderboard
14. 14.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Kabir", "Zoya", "Meera", "Riya"];
    show(friends[1]); (a) Zoya (b) Kabir (c) Meera (d) Arjun
15. 15.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
16. 16.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
17. 17.Which of these fits saving on the phone? (a) your last game level (b) chat messages to friends (c) photos on two devices (d) a class leaderboard
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Kabir", "Zoya"];
    show(friends[1]); (a) Kabir (b) Zoya (c) Arjun (d) Riya
19. 19.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
20. 20.💾 What number does this code show?
    let coins = 5;
    coins = coins - 5;
    coins = coins + 2;
    show(coins);
21. 21.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
22. 22.💾 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
23. 23.💾 What number does this code show?
    let stars = 5;
    stars = stars - 2;
    stars = stars + 2;
    show(stars);
24. 24.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
25. 25.💾 What number does this code show?
    let score = 9;
    score = score - 4;
    score = score + 3;
    show(score);
26. 26.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Science"];
    show(notes[2]); (a) Maths (b) Science (c) Sports
27. 27.💾 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) Art (b) Science (c) Sports (d) Maths
28. 28.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 1 (c) 10 (d) 2
29. 29.💾 What number does this code show?
    let songs = ["Rain", "Sunrise", "Kites"];
    songs.push("Ocean");
    songs.push("Stars");
    show(songs.length);
30. 30.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) notes to read offline (d) chat messages to friends
31. 31.💾 What number does this code show?
    let songs = ["Kites", "Stars"];
    songs.push("Sunrise");
    show(songs.length);
32. 32.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
33. 33.💾 What number does this code show?
    let notes = ["Art", "Hindi", "Science"];
    notes.push("Maths");
    show(notes.length);
34. 34.💾 What number does this code show?
    let friends = ["Arjun", "Kabir", "Riya", "Meera"];
    friends.push("Zoya");
    show(friends.length);
35. 35.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Music", "Hindi"];
    show(notes[0]); (a) Music (b) Science (c) Hindi
36. 36.True or false: photos on two devices fits saving on the phone. (a) True (b) False
37. 37.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
38. 38.💾 What number does this code show?
    let friends = ["Arjun", "Riya", "Meera", "Zoya"];
    friends.push("Kabir");
    show(friends.length);
39. 39.💾 What number does this code show?
    let notes = ["Music", "Maths"];
    notes.push("Science");
    show(notes.length);
40. 40.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Sunrise", "Kites", "Stars", "Rain"];
    show(songs[3]); (a) Ocean (b) Stars (c) Sunrise (d) Kites

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