App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 92 · 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: the sound on/off setting fits saving on the phone. (a) True (b) False
2. 2.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
3. 3.💾 What is a variable? (a) a named box for a value (b) a type of screen (c) a phone setting (d) a picture
4. 4.💾 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
5. 5.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) on the phone (b) in the cloud
6. 6.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
7. 7.True or false: photos on two devices fits saving on the phone. (a) False (b) True
8. 8.💾 What number does this code show?
   let points = 9;
   points = points - 5;
   points = points + 2;
   show(points);
9. 9.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) chat messages to friends (d) a draft you are typing
10. 10.💾 What number does this code show?
    let friends = ["Riya", "Aman", "Zoya", "Arjun"];
    friends.push("Kabir");
    show(friends.length);
11. 11.💾 What number does this code show?
    let score = 8;
    score = score - 1;
    score = score + 1;
    show(score);
12. 12.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
13. 13.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Arjun", "Riya", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Zoya (c) Riya (d) Aman
14. 14.💾 What number does this code show?
    let score = 6;
    score = score - 4;
    score = score + 4;
    show(score);
15. 15.Which of these fits saving on the phone? (a) notes to read offline (b) photos on two devices (c) a shared to-do list (d) a class leaderboard
16. 16.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Rain", "Monsoon"];
    show(songs[2]); (a) Sunrise (b) Monsoon (c) Rain
17. 17.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Hindi", "Sports", "Art"];
    show(notes[1]); (a) Hindi (b) Science (c) Art (d) Sports
18. 18.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
19. 19.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
20. 20.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
21. 21.Which of these fits saving on the phone? (a) a class leaderboard (b) a draft you are typing (c) a shared to-do list (d) photos on two devices
22. 22.💾 What number does this code show?
    let songs = ["Rain", "Kites"];
    songs.push("Monsoon");
    songs.push("Ocean");
    show(songs.length);
23. 23.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) use it on any device (d) skip the internet
24. 24.Which of these fits saving in the cloud? (a) notes to read offline (b) photos on two devices (c) the sound on/off setting (d) a draft you are typing
25. 25.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Music", "Maths", "Sports", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Music (c) Sports (d) Hindi
26. 26.💾 What number does this code show?
    let notes = ["Hindi", "Maths", "Science", "Sports"];
    notes.push("Music");
    show(notes.length);
27. 27.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 2 (d) 0
28. 28.Which of these fits saving on the phone? (a) the sound on/off setting (b) a shared to-do list (c) a class leaderboard (d) chat messages to friends
29. 29.💾 What number does this code show?
    let songs = ["Stars", "Monsoon", "Kites"];
    songs.push("Ocean");
    show(songs.length);
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Music", "Hindi", "Maths", "Art"];
    show(notes[3]); (a) Hindi (b) Music (c) Maths (d) Sports
31. 31.Which of these fits saving in the cloud? (a) notes to read offline (b) a shared to-do list (c) the sound on/off setting (d) a draft you are typing
32. 32.Which of these fits saving on the phone? (a) your last game level (b) photos on two devices (c) a shared to-do list (d) a class leaderboard
33. 33.💾 What number does this code show?
    let lives = 8;
    lives = lives - 2;
    lives = lives + 2;
    show(lives);
34. 34.💾 What number does this code show?
    let points = 5;
    points = points - 4;
    points = points + 2;
    show(points);
35. 35.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
36. 36.💾 What number does this code show?
    let score = 3;
    score = score - 2;
    score = score + 1;
    show(score);
37. 37.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
38. 38.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Hindi", "Sports", "Maths"];
    show(notes[1]); (a) Art (b) Sports (c) Music (d) Hindi
39. 39.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
40. 40.💾 Which can hold many values in order? (a) a list (b) a button (c) a single number (d) a switch

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