App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 249 · 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.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the phone is lost (c) the app is closed (d) the screen turns off
2. 2.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Monsoon", "Sunrise"];
   show(songs[0]); (a) Sunrise (b) Ocean (c) Monsoon
3. 3.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a class leaderboard (d) notes to read offline
4. 4.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Kites", "Rain", "Monsoon"];
   show(songs[1]); (a) Kites (b) Monsoon (c) Rain (d) Ocean
5. 5.💾 What does this code show? (Positions start at 0.)
   let friends = ["Riya", "Meera", "Aman"];
   show(friends[1]); (a) Aman (b) Meera (c) Riya
6. 6.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
7. 7.💾 What number does this code show?
   let notes = ["Art", "Music", "Hindi", "Maths"];
   notes.push("Sports");
   show(notes.length);
8. 8.💾 What does this code show? (Positions start at 0.)
   let songs = ["Rain", "Stars", "Monsoon"];
   show(songs[0]); (a) Monsoon (b) Rain (c) Stars
9. 9.💾 pop() takes off the last item. What does this code show?
   let songs = ["Stars", "Kites", "Ocean", "Rain"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Kites (d) Stars
10. 10.💾 What number does this code show?
    let songs = ["Ocean", "Stars", "Monsoon", "Rain"];
    songs.push("Sunrise");
    songs.push("Kites");
    show(songs.length);
11. 11.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) a draft you are typing (d) photos on two devices
12. 12.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
13. 13.💾 What number does this code show?
    let coins = 9;
    coins = coins - 8;
    coins = coins + 5;
    show(coins);
14. 14.💾 Which can hold many values in order? (a) a single number (b) a button (c) a list (d) a switch
15. 15.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
16. 16.💾 What number does this code show?
    let stars = 5;
    stars = stars - 5;
    stars = stars + 5;
    show(stars);
17. 17.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) chat messages to friends (d) notes to read offline
18. 18.💾 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
19. 19.💾 Which works with no internet at all? (a) a cloud backup (b) a shared chat (c) a cloud leaderboard (d) data saved on the phone
20. 20.💾 What number does this code show?
    let lives = 7;
    lives = lives - 2;
    lives = lives + 5;
    show(lives);
21. 21.💾 What number does this code show?
    let notes = ["Art", "Music", "Sports"];
    notes.push("Science");
    notes.push("Hindi");
    show(notes.length);
22. 22.Which of these fits saving in the cloud? (a) a draft you are typing (b) a shared to-do list (c) the sound on/off setting (d) your last game level
23. 23.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
24. 24.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Zoya", "Aman"];
    show(friends[0]); (a) Zoya (b) Kabir (c) Aman
25. 25.💾 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
26. 26.True or false: your last game level fits saving in the cloud. (a) True (b) False
27. 27.True or false: photos on two devices fits saving on the phone. (a) True (b) False
28. 28.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Science", "Art"];
    show(notes[2]); (a) Art (b) Music (c) Science
29. 29.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Monsoon", "Sunrise", "Rain", "Kites"];
    show(songs[0]); (a) Rain (b) Monsoon (c) Ocean (d) Sunrise
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Rain", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Ocean (c) Stars
31. 31.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) your last game level (d) a shared to-do list
32. 32.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Hindi", "Sports", "Science"];
    show(notes[2]); (a) Maths (b) Hindi (c) Sports (d) Art
33. 33.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
34. 34.💾 What number does this code show?
    let notes = ["Science", "Music"];
    notes.push("Hindi");
    notes.push("Sports");
    show(notes.length);
35. 35.💾 What number does this code show?
    let score = 6;
    score = score - 1;
    score = score + 5;
    show(score);
36. 36.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
37. 37.💾 What is a variable? (a) a picture (b) a type of screen (c) a named box for a value (d) a phone setting
38. 38.💾 What number does this code show?
    let friends = ["Zoya", "Kabir", "Meera"];
    friends.push("Aman");
    friends.push("Riya");
    show(friends.length);
39. 39.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
40. 40.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Kabir", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Meera

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