App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 305 · 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) True (b) False
2. 2.💾 Which works with no internet at all? (a) a cloud leaderboard (b) data saved on the phone (c) a shared chat (d) a cloud backup
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Kites", "Sunrise", "Rain", "Monsoon"];
   show(songs[0]); (a) Sunrise (b) Monsoon (c) Rain (d) Kites
4. 4.💾 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
5. 5.💾 pop() takes off the last item. What does this code show?
   let friends = ["Riya", "Kabir", "Meera", "Zoya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Meera (d) Riya
6. 6.True or false: your last game level fits saving on the phone. (a) False (b) True
7. 7.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a named box for a value (d) a picture
8. 8.💾 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
9. 9.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
10. 10.💾 What number does this code show?
    let lives = 6;
    lives = lives - 4;
    lives = lives + 3;
    show(lives);
11. 11.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Music", "Hindi"];
    show(notes[1]); (a) Sports (b) Music (c) Maths (d) Hindi
12. 12.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
13. 13.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 4;
    show(score);
14. 14.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Ocean", "Stars", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Ocean (c) Rain (d) Monsoon
15. 15.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Music", "Sports", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Science (c) Sports (d) Art
16. 16.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) you send a message (c) the app is closed (d) the screen turns off
17. 17.💾 What number does this code show?
    let lives = 5;
    lives = lives - 4;
    lives = lives + 2;
    show(lives);
18. 18.💾 What number does this code show?
    let songs = ["Ocean", "Kites", "Stars"];
    songs.push("Sunrise");
    show(songs.length);
19. 19.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Kabir", "Aman", "Meera", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Aman (c) Riya (d) Meera
20. 20.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
21. 21.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Stars", "Sunrise"];
    show(songs[0]); (a) Kites (b) Sunrise (c) Stars (d) Monsoon
22. 22.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
23. 23.💾 What number does this code show?
    let friends = ["Zoya", "Arjun", "Riya", "Aman"];
    friends.push("Kabir");
    show(friends.length);
24. 24.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Music", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Sports (c) Maths
25. 25.💾 Where should the app save chat messages to friends: 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) your last game level (b) a shared to-do list (c) chat messages to friends (d) a class leaderboard
27. 27.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) on the phone (b) in the cloud
28. 28.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) a class leaderboard (d) a draft you are typing
29. 29.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
30. 30.💾 What number does this code show?
    let notes = ["Maths", "Art", "Music"];
    notes.push("Science");
    notes.push("Sports");
    show(notes.length);
31. 31.💾 What number does this code show?
    let score = 6;
    score = score - 6;
    score = score + 1;
    show(score);
32. 32.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
33. 33.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
34. 34.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
35. 35.💾 What number does this code show?
    let coins = 4;
    coins = coins - 1;
    coins = coins + 4;
    show(coins);
36. 36.💾 What number does this code show?
    let notes = ["Science", "Maths", "Music"];
    notes.push("Art");
    show(notes.length);
37. 37.💾 What number does this code show?
    let lives = 6;
    lives = lives - 6;
    lives = lives + 1;
    show(lives);
38. 38.💾 What number does this code show?
    let notes = ["Art", "Sports", "Hindi"];
    notes.push("Music");
    show(notes.length);
39. 39.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 2 (d) 0
40. 40.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Aman", "Meera", "Zoya", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Meera (c) Arjun (d) Zoya

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