App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 517 · 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 coins = 6;
   coins = coins - 1;
   coins = coins + 1;
   show(coins);
2. 2.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
3. 3.💾 What is a variable? (a) a type of screen (b) a picture (c) a phone setting (d) a named box for a value
4. 4.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
5. 5.💾 pop() takes off the last item. What does this code show?
   let notes = ["Science", "Art", "Maths"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Science (b) Art (c) Maths
6. 6.💾 What number does this code show?
   let notes = ["Music", "Hindi", "Sports", "Art"];
   notes.push("Maths");
   show(notes.length);
7. 7.💾 What number does this code show?
   let friends = ["Riya", "Kabir"];
   friends.push("Arjun");
   show(friends.length);
8. 8.💾 What number does this code show?
   let songs = ["Kites", "Ocean", "Rain", "Stars"];
   songs.push("Sunrise");
   show(songs.length);
9. 9.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
10. 10.True or false: notes to read offline fits saving on the phone. (a) False (b) True
11. 11.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
13. 13.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Science", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Science (c) Sports
14. 14.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) photos on two devices (d) notes to read offline
15. 15.💾 What number does this code show?
    let points = 5;
    points = points - 5;
    points = points + 4;
    show(points);
16. 16.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) never need a password (c) skip the internet (d) shrink the app
17. 17.💾 What number does this code show?
    let notes = ["Art", "Science"];
    notes.push("Maths");
    show(notes.length);
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Arjun", "Kabir", "Zoya"];
    show(friends[3]); (a) Zoya (b) Riya (c) Arjun (d) Kabir
19. 19.💾 What number does this code show?
    let songs = ["Sunrise", "Rain", "Kites"];
    songs.push("Stars");
    show(songs.length);
20. 20.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Science", "Music"];
    show(notes[3]); (a) Maths (b) Science (c) Music (d) Art
21. 21.True or false: photos on two devices fits saving on the phone. (a) True (b) False
22. 22.Which of these fits saving in the cloud? (a) notes to read offline (b) chat messages to friends (c) a draft you are typing (d) the sound on/off setting
23. 23.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a draft you are typing (d) a shared to-do list
24. 24.💾 What number does this code show?
    let songs = ["Kites", "Rain"];
    songs.push("Sunrise");
    songs.push("Monsoon");
    show(songs.length);
25. 25.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) notes to read offline (d) photos on two devices
26. 26.💾 What number does this code show?
    let lives = 9;
    lives = lives - 1;
    lives = lives + 3;
    show(lives);
27. 27.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
28. 28.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Sports", "Science", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Sports (c) Hindi (d) Art
29. 29.Which of these fits saving in the cloud? (a) a class leaderboard (b) your last game level (c) notes to read offline (d) the sound on/off setting
30. 30.💾 What number does this code show?
    let points = 9;
    points = points - 8;
    points = points + 3;
    show(points);
31. 31.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) the sound on/off setting (d) chat messages to friends
32. 32.💾 Which works with no internet at all? (a) data saved on the phone (b) a shared chat (c) a cloud backup (d) a cloud leaderboard
33. 33.💾 What number does this code show?
    let coins = 9;
    coins = coins - 5;
    coins = coins + 1;
    show(coins);
34. 34.💾 What number does this code show?
    let songs = ["Ocean", "Kites"];
    songs.push("Stars");
    show(songs.length);
35. 35.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
36. 36.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
37. 37.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Ocean", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Sunrise (c) Ocean
39. 39.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
40. 40.💾 What number does this code show?
    let coins = 8;
    coins = coins - 1;
    coins = coins + 1;
    show(coins);

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