App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 539 · 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 number does this code show?
   let notes = ["Music", "Art", "Hindi", "Maths"];
   notes.push("Science");
   notes.push("Sports");
   show(notes.length);
2. 2.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
3. 3.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
4. 4.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
5. 5.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
6. 6.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.💾 What does this code show? (Positions start at 0.)
   let notes = ["Art", "Music", "Maths", "Hindi"];
   show(notes[1]); (a) Maths (b) Hindi (c) Music (d) Art
8. 8.💾 What number does this code show?
   let lives = 8;
   lives = lives - 6;
   lives = lives + 1;
   show(lives);
9. 9.Which of these fits saving on the phone? (a) a class leaderboard (b) a draft you are typing (c) photos on two devices (d) chat messages to friends
10. 10.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a draft you are typing (d) chat messages to friends
11. 11.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Stars", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Kites
12. 12.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
13. 13.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Hindi", "Maths", "Music", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Hindi (d) Music
14. 14.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Kites", "Ocean", "Sunrise"];
    show(songs[2]); (a) Kites (b) Ocean (c) Sunrise (d) Rain
15. 15.💾 What number does this code show?
    let notes = ["Art", "Hindi", "Sports"];
    notes.push("Science");
    notes.push("Maths");
    show(notes.length);
16. 16.True or false: notes to read offline fits saving on the phone. (a) False (b) True
17. 17.💾 What number does this code show?
    let lives = 9;
    lives = lives - 7;
    lives = lives + 2;
    show(lives);
18. 18.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 3;
    show(coins);
19. 19.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Sports", "Hindi", "Maths", "Art"];
    show(notes[0]); (a) Sports (b) Maths (c) Hindi (d) Music
20. 20.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) the sound on/off setting (d) chat messages to friends
21. 21.💾 Which works with no internet at all? (a) a shared chat (b) data saved on the phone (c) a cloud backup (d) a cloud leaderboard
22. 22.💾 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
23. 23.Which of these fits saving in the cloud? (a) a draft you are typing (b) a class leaderboard (c) notes to read offline (d) the sound on/off setting
24. 24.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Art", "Science"];
    show(notes[3]); (a) Maths (b) Music (c) Art (d) Science
25. 25.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the phone is lost (d) the screen turns off
26. 26.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
27. 27.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
28. 28.💾 What number does this code show?
    let songs = ["Stars", "Ocean"];
    songs.push("Monsoon");
    songs.push("Rain");
    show(songs.length);
29. 29.💾 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
30. 30.💾 What number does this code show?
    let friends = ["Riya", "Zoya"];
    friends.push("Arjun");
    friends.push("Meera");
    show(friends.length);
31. 31.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 10 (d) 2
32. 32.💾 What number does this code show?
    let friends = ["Riya", "Meera", "Zoya", "Arjun"];
    friends.push("Aman");
    show(friends.length);
33. 33.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
34. 34.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
35. 35.Which of these fits saving in the cloud? (a) the sound on/off setting (b) photos on two devices (c) notes to read offline (d) your last game level
36. 36.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) notes to read offline
37. 37.💾 What number does this code show?
    let notes = ["Art", "Sports", "Music"];
    notes.push("Science");
    notes.push("Hindi");
    show(notes.length);
38. 38.💾 What number does this code show?
    let coins = 5;
    coins = coins - 2;
    coins = coins + 2;
    show(coins);
39. 39.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Aman", "Zoya"];
    show(friends[2]); (a) Zoya (b) Arjun (c) Aman
40. 40.💾 Which can hold many values in order? (a) a button (b) a list (c) a single number (d) a switch

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