App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 123 · 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.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
2. 2.💾 Which can hold many values in order? (a) a single number (b) a button (c) a switch (d) a list
3. 3.💾 What number does this code show?
   let notes = ["Science", "Art", "Music"];
   notes.push("Sports");
   show(notes.length);
4. 4.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
5. 5.Which of these fits saving on the phone? (a) the sound on/off setting (b) photos on two devices (c) a shared to-do list (d) a class leaderboard
6. 6.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) photos on two devices (d) a shared to-do list
7. 7.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) a shared to-do list (d) notes to read offline
8. 8.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.💾 What number does this code show?
   let friends = ["Arjun", "Zoya"];
   friends.push("Riya");
   show(friends.length);
10. 10.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a picture (d) a type of screen
11. 11.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Riya", "Kabir", "Aman"];
    show(friends[3]); (a) Kabir (b) Zoya (c) Riya (d) Aman
12. 12.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
13. 13.💾 What number does this code show?
    let points = 7;
    points = points - 3;
    points = points + 2;
    show(points);
14. 14.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
15. 15.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 2 (d) 10
16. 16.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) in the cloud (b) on the phone
17. 17.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) never need a password (c) use it on any device (d) shrink the app
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Zoya", "Arjun"];
    show(friends[2]); (a) Aman (b) Arjun (c) Zoya (d) Riya
19. 19.💾 What number does this code show?
    let songs = ["Rain", "Monsoon"];
    songs.push("Ocean");
    songs.push("Sunrise");
    show(songs.length);
20. 20.💾 What number does this code show?
    let songs = ["Stars", "Rain", "Kites", "Monsoon"];
    songs.push("Ocean");
    show(songs.length);
21. 21.True or false: your last game level fits saving on the phone. (a) True (b) False
22. 22.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Science", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Music (c) Science
23. 23.Which of these fits saving on the phone? (a) a draft you are typing (b) chat messages to friends (c) a shared to-do list (d) a class leaderboard
24. 24.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Monsoon", "Sunrise"];
    show(songs[2]); (a) Stars (b) Sunrise (c) Monsoon
25. 25.💾 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
26. 26.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) you send a message (c) the screen turns off (d) the app is closed
27. 27.💾 What number does this code show?
    let friends = ["Arjun", "Kabir", "Aman", "Zoya"];
    friends.push("Meera");
    friends.push("Riya");
    show(friends.length);
28. 28.💾 What number does this code show?
    let lives = 4;
    lives = lives - 2;
    lives = lives + 5;
    show(lives);
29. 29.💾 What number does this code show?
    let notes = ["Sports", "Maths", "Art"];
    notes.push("Science");
    notes.push("Music");
    show(notes.length);
30. 30.💾 What number does this code show?
    let songs = ["Stars", "Sunrise", "Rain", "Monsoon"];
    songs.push("Ocean");
    songs.push("Kites");
    show(songs.length);
31. 31.💾 What number does this code show?
    let friends = ["Arjun", "Riya", "Meera"];
    friends.push("Zoya");
    show(friends.length);
32. 32.💾 What number does this code show?
    let notes = ["Science", "Hindi"];
    notes.push("Maths");
    show(notes.length);
33. 33.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Rain", "Stars", "Monsoon", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Kites (c) Stars (d) Monsoon
34. 34.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Ocean", "Sunrise", "Stars"];
    show(songs[0]); (a) Sunrise (b) Stars (c) Kites (d) Ocean
35. 35.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Kites", "Rain"];
    show(songs[2]); (a) Rain (b) Kites (c) Ocean
36. 36.💾 What number does this code show?
    let lives = 4;
    lives = lives - 3;
    lives = lives + 1;
    show(lives);
37. 37.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) a shared chat (d) data saved on the phone
38. 38.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a class leaderboard (d) your last game level
39. 39.💾 What number does this code show?
    let coins = 4;
    coins = coins - 2;
    coins = coins + 1;
    show(coins);
40. 40.💾 What number does this code show?
    let friends = ["Riya", "Aman", "Kabir"];
    friends.push("Arjun");
    show(friends.length);

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