App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 514 · 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 does this code show? (Positions start at 0.)
   let songs = ["Sunrise", "Rain", "Ocean", "Kites", "Monsoon"];
   show(songs[0]); (a) Ocean (b) Sunrise (c) Kites (d) Rain
2. 2.True or false: notes to read offline fits saving on the phone. (a) False (b) True
3. 3.💾 pop() takes off the last item. What does this code show?
   let songs = ["Monsoon", "Rain", "Ocean", "Stars"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Monsoon (b) Rain (c) Stars (d) Ocean
4. 4.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
5. 5.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) never need a password (c) skip the internet (d) shrink the app
6. 6.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
8. 8.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
9. 9.True or false: photos on two devices fits saving on the phone. (a) True (b) False
10. 10.💾 What number does this code show?
    let coins = 7;
    coins = coins - 3;
    coins = coins + 1;
    show(coins);
11. 11.Which of these fits saving on the phone? (a) a shared to-do list (b) your last game level (c) a class leaderboard (d) photos on two devices
12. 12.💾 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
13. 13.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the phone is lost (c) the app is closed (d) you send a message
14. 14.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Maths", "Art"];
    show(notes[2]); (a) Maths (b) Sports (c) Art
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Sports", "Science", "Art"];
    show(notes[4]); (a) Music (b) Sports (c) Maths (d) Art
16. 16.💾 Which can hold many values in order? (a) a single number (b) a list (c) a button (d) a switch
17. 17.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Hindi", "Art", "Maths"];
    show(notes[1]); (a) Music (b) Maths (c) Art (d) Hindi
18. 18.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
19. 19.True or false: your last game level fits saving in the cloud. (a) True (b) False
20. 20.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 0 (d) 2
21. 21.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
22. 22.💾 What number does this code show?
    let stars = 8;
    stars = stars - 6;
    stars = stars + 4;
    show(stars);
23. 23.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
24. 24.💾 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
25. 25.💾 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
26. 26.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) notes to read offline (d) a class leaderboard
27. 27.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Monsoon", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Kites (c) Ocean
28. 28.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Monsoon", "Rain", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Stars (d) Monsoon
29. 29.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) a shared chat (d) data saved on the phone
30. 30.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Aman", "Arjun"];
    show(friends[0]); (a) Aman (b) Kabir (c) Arjun
31. 31.💾 What number does this code show?
    let friends = ["Meera", "Aman", "Arjun"];
    friends.push("Riya");
    show(friends.length);
32. 32.💾 What is a variable? (a) a picture (b) a phone setting (c) a type of screen (d) a named box for a value
33. 33.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
34. 34.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
35. 35.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Maths", "Music", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Music (c) Sports (d) Art
36. 36.Which of these fits saving in the cloud? (a) photos on two devices (b) a draft you are typing (c) notes to read offline (d) the sound on/off setting
37. 37.Which of these fits saving in the cloud? (a) your last game level (b) chat messages to friends (c) the sound on/off setting (d) notes to read offline
38. 38.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Rain", "Stars", "Monsoon", "Ocean"];
    show(songs[0]); (a) Monsoon (b) Rain (c) Sunrise (d) Stars
39. 39.Which of these fits saving in the cloud? (a) a shared to-do list (b) the sound on/off setting (c) notes to read offline (d) your last game level
40. 40.💾 What number does this code show?
    let notes = ["Art", "Maths", "Science"];
    notes.push("Sports");
    show(notes.length);

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