App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 319 · 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 is a variable? (a) a picture (b) a type of screen (c) a phone setting (d) a named box for a value
2. 2.💾 What number does this code show?
   let points = 8;
   points = points - 2;
   points = points + 5;
   show(points);
3. 3.💾 pop() takes off the last item. What does this code show?
   let notes = ["Art", "Maths", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Art (b) Sports (c) Maths
4. 4.💾 What does this code show? (Positions start at 0.)
   let friends = ["Aman", "Riya", "Zoya", "Kabir"];
   show(friends[0]); (a) Aman (b) Kabir (c) Zoya (d) Riya
5. 5.💾 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
6. 6.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
7. 7.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
8. 8.Which of these fits saving on the phone? (a) the sound on/off setting (b) photos on two devices (c) a class leaderboard (d) chat messages to friends
9. 9.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) on the phone (b) in the cloud
10. 10.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
11. 11.💾 What number does this code show?
    let songs = ["Kites", "Monsoon"];
    songs.push("Stars");
    show(songs.length);
12. 12.Which of these fits saving on the phone? (a) a draft you are typing (b) a shared to-do list (c) chat messages to friends (d) photos on two devices
13. 13.💾 What number does this code show?
    let lives = 6;
    lives = lives - 5;
    lives = lives + 1;
    show(lives);
14. 14.💾 What number does this code show?
    let score = 3;
    score = score - 3;
    score = score + 5;
    show(score);
15. 15.💾 What number does this code show?
    let songs = ["Sunrise", "Stars"];
    songs.push("Monsoon");
    show(songs.length);
16. 16.Which of these fits saving in the cloud? (a) a shared to-do list (b) your last game level (c) a draft you are typing (d) the sound on/off setting
17. 17.💾 What number does this code show?
    let notes = ["Music", "Sports", "Maths", "Art"];
    notes.push("Hindi");
    notes.push("Science");
    show(notes.length);
18. 18.💾 What number does this code show?
    let notes = ["Music", "Sports", "Maths"];
    notes.push("Hindi");
    show(notes.length);
19. 19.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 1 (d) 10
20. 20.💾 What number does this code show?
    let friends = ["Meera", "Zoya", "Arjun", "Aman"];
    friends.push("Riya");
    friends.push("Kabir");
    show(friends.length);
21. 21.Which of these fits saving in the cloud? (a) the sound on/off setting (b) photos on two devices (c) your last game level (d) notes to read offline
22. 22.True or false: notes to read offline fits saving on the phone. (a) False (b) True
23. 23.💾 What number does this code show?
    let songs = ["Stars", "Kites"];
    songs.push("Monsoon");
    show(songs.length);
24. 24.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
25. 25.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
26. 26.💾 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
27. 27.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Maths", "Music"];
    show(notes[1]); (a) Music (b) Maths (c) Science
28. 28.💾 What number does this code show?
    let coins = 6;
    coins = coins - 1;
    coins = coins + 4;
    show(coins);
29. 29.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) a class leaderboard (d) notes to read offline
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Sports", "Hindi", "Science"];
    show(notes[4]); (a) Science (b) Music (c) Art (d) Sports
31. 31.True or false: your last game level fits saving on the phone. (a) False (b) True
32. 32.Which of these fits saving in the cloud? (a) notes to read offline (b) a class leaderboard (c) the sound on/off setting (d) your last game level
33. 33.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Kites", "Ocean"];
    show(songs[0]); (a) Kites (b) Sunrise (c) Ocean
34. 34.💾 What number does this code show?
    let stars = 4;
    stars = stars - 2;
    stars = stars + 4;
    show(stars);
35. 35.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) data saved on the phone (d) a shared chat
36. 36.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) skip the internet (c) never need a password (d) use it on any device
37. 37.💾 What number does this code show?
    let points = 8;
    points = points - 6;
    points = points + 1;
    show(points);
38. 38.💾 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
39. 39.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Rain", "Kites", "Stars", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Ocean (c) Stars (d) Rain

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