App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 725 · 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 notes = ["Maths", "Science", "Hindi", "Music"];
   show(notes[0]); (a) Hindi (b) Science (c) Maths (d) Music
2. 2.💾 What number does this code show?
   let notes = ["Hindi", "Maths"];
   notes.push("Science");
   show(notes.length);
3. 3.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.💾 What does this code show? (Positions start at 0.)
   let notes = ["Maths", "Sports", "Music"];
   show(notes[1]); (a) Maths (b) Sports (c) Music
5. 5.💾 What does this code show? (Positions start at 0.)
   let notes = ["Music", "Art", "Sports"];
   show(notes[1]); (a) Music (b) Sports (c) Art
6. 6.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
7. 7.Which of these fits saving in the cloud? (a) photos on two devices (b) notes to read offline (c) the sound on/off setting (d) a draft you are typing
8. 8.💾 What number does this code show?
   let friends = ["Arjun", "Zoya"];
   friends.push("Kabir");
   show(friends.length);
9. 9.💾 pop() takes off the last item. What does this code show?
   let songs = ["Monsoon", "Stars", "Rain", "Ocean"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Ocean (b) Monsoon (c) Stars (d) Rain
10. 10.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Monsoon", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Monsoon (c) Kites
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.💾 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
13. 13.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Kites", "Rain", "Sunrise"];
    show(songs[2]); (a) Sunrise (b) Rain (c) Kites (d) Stars
14. 14.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
15. 15.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
16. 16.💾 What number does this code show?
    let coins = 9;
    coins = coins - 9;
    coins = coins + 2;
    show(coins);
17. 17.💾 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
18. 18.💾 What number does this code show?
    let friends = ["Aman", "Zoya", "Arjun", "Kabir"];
    friends.push("Meera");
    show(friends.length);
19. 19.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
20. 20.Which of these fits saving on the phone? (a) your last game level (b) a class leaderboard (c) chat messages to friends (d) photos on two devices
21. 21.💾 What number does this code show?
    let notes = ["Maths", "Music"];
    notes.push("Hindi");
    show(notes.length);
22. 22.💾 What number does this code show?
    let songs = ["Rain", "Stars"];
    songs.push("Ocean");
    show(songs.length);
23. 23.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Monsoon"];
    show(songs[0]); (a) Sunrise (b) Kites (c) Monsoon
24. 24.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Art", "Maths", "Science"];
    show(notes[3]); (a) Maths (b) Science (c) Art (d) Hindi
25. 25.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Maths", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Hindi (c) Maths
26. 26.Which of these fits saving on the phone? (a) a shared to-do list (b) the sound on/off setting (c) photos on two devices (d) chat messages to friends
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Ocean", "Monsoon", "Stars"];
    show(songs[1]); (a) Monsoon (b) Ocean (c) Kites (d) Sunrise
28. 28.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a picture (d) a type of screen
29. 29.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the app is closed (c) the phone is lost (d) you send a message
30. 30.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Music", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Hindi (c) Music
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Kites", "Stars", "Sunrise"];
    show(songs[2]); (a) Sunrise (b) Stars (c) Rain (d) Kites
32. 32.Which of these fits saving in the cloud? (a) the sound on/off setting (b) chat messages to friends (c) notes to read offline (d) a draft you are typing
33. 33.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) a class leaderboard (d) a draft you are typing
34. 34.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
35. 35.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Art", "Science"];
    show(notes[2]); (a) Science (b) Sports (c) Art
36. 36.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 1 (d) 10
37. 37.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) use it on any device (d) skip the internet
38. 38.Which of these fits saving on the phone? (a) a class leaderboard (b) notes to read offline (c) chat messages to friends (d) a shared to-do list
39. 39.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Zoya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Zoya
40. 40.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Science", "Maths", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Maths (c) Art (d) Science

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