App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 973 · 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.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the app is closed (c) the screen turns off (d) the phone is lost
2. 2.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
3. 3.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.💾 pop() takes off the last item. What does this code show?
   let songs = ["Sunrise", "Rain", "Monsoon", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Rain (d) Monsoon
5. 5.Which of these fits saving in the cloud? (a) chat messages to friends (b) the sound on/off setting (c) a draft you are typing (d) your last game level
6. 6.💾 What number does this code show?
   let lives = 6;
   lives = lives - 1;
   lives = lives + 5;
   show(lives);
7. 7.💾 What number does this code show?
   let friends = ["Aman", "Meera", "Kabir"];
   friends.push("Arjun");
   friends.push("Riya");
   show(friends.length);
8. 8.💾 Saving data in the cloud lets you ___. (a) never need a password (b) use it on any device (c) shrink the app (d) skip the internet
9. 9.💾 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
10. 10.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
11. 11.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 2 (d) 0
12. 12.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
13. 13.True or false: your last game level fits saving on the phone. (a) False (b) True
14. 14.💾 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
15. 15.💾 What number does this code show?
    let friends = ["Arjun", "Meera", "Riya", "Aman"];
    friends.push("Zoya");
    show(friends.length);
16. 16.💾 What number does this code show?
    let lives = 7;
    lives = lives - 7;
    lives = lives + 4;
    show(lives);
17. 17.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Arjun", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Kabir (c) Zoya
18. 18.True or false: photos on two devices fits saving on the phone. (a) False (b) True
19. 19.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) a draft you are typing (d) a shared to-do list
20. 20.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) a class leaderboard (d) notes to read offline
21. 21.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Hindi (c) Art
22. 22.💾 What number does this code show?
    let points = 6;
    points = points - 1;
    points = points + 5;
    show(points);
23. 23.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Maths", "Science", "Art", "Hindi"];
    show(notes[3]); (a) Science (b) Art (c) Maths (d) Sports
24. 24.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Hindi (c) Science
25. 25.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Sports", "Maths", "Music", "Art"];
    show(notes[1]); (a) Music (b) Maths (c) Sports (d) Science
26. 26.Which of these fits saving in the cloud? (a) the sound on/off setting (b) photos on two devices (c) your last game level (d) a draft you are typing
27. 27.True or false: notes to read offline fits saving on the phone. (a) True (b) False
28. 28.💾 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
29. 29.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Sports", "Hindi", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Sports (c) Hindi (d) Art
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Sunrise", "Ocean", "Rain", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Ocean (c) Rain (d) Stars
31. 31.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
32. 32.💾 What number does this code show?
    let score = 4;
    score = score - 4;
    score = score + 2;
    show(score);
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.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Hindi", "Music"];
    show(notes[2]); (a) Sports (b) Hindi (c) Music
35. 35.💾 What number does this code show?
    let coins = 7;
    coins = coins - 6;
    coins = coins + 2;
    show(coins);
36. 36.💾 What number does this code show?
    let lives = 9;
    lives = lives - 1;
    lives = lives + 1;
    show(lives);
37. 37.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Arjun", "Riya"];
    show(friends[1]); (a) Zoya (b) Riya (c) Arjun
38. 38.💾 What is a variable? (a) a picture (b) a phone setting (c) a type of screen (d) a named box for a value
39. 39.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Hindi", "Music"];
    show(notes[2]); (a) Hindi (b) Art (c) Music (d) Maths
40. 40.True or false: notes to read offline fits saving in the cloud. (a) True (b) False

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