App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 74 · 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 songs = ["Sunrise", "Rain"];
   songs.push("Stars");
   songs.push("Kites");
   show(songs.length);
2. 2.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) use it on any device (d) skip the internet
3. 3.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
4. 4.💾 What does this code show? (Positions start at 0.)
   let notes = ["Sports", "Music", "Maths", "Art"];
   show(notes[0]); (a) Music (b) Maths (c) Art (d) Sports
5. 5.True or false: your last game level fits saving on the phone. (a) False (b) True
6. 6.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
7. 7.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
8. 8.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Art", "Science"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Science (b) Maths (c) Art
9. 9.💾 What number does this code show?
   let coins = 7;
   coins = coins - 6;
   coins = coins + 3;
   show(coins);
10. 10.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
11. 11.💾 What number does this code show?
    let friends = ["Aman", "Arjun"];
    friends.push("Riya");
    friends.push("Kabir");
    show(friends.length);
12. 12.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a shared chat (c) data saved on the phone (d) a cloud backup
13. 13.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 0 (d) 10
14. 14.💾 What number does this code show?
    let coins = 6;
    coins = coins - 5;
    coins = coins + 4;
    show(coins);
15. 15.💾 What number does this code show?
    let lives = 3;
    lives = lives - 2;
    lives = lives + 2;
    show(lives);
16. 16.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Science", "Hindi", "Sports", "Art"];
    show(notes[4]); (a) Hindi (b) Art (c) Science (d) Music
17. 17.💾 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
18. 18.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a shared to-do list (d) your last game level
19. 19.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Kabir", "Aman", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Meera (c) Kabir (d) Aman
20. 20.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
21. 21.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
22. 22.💾 What number does this code show?
    let friends = ["Meera", "Kabir"];
    friends.push("Zoya");
    friends.push("Arjun");
    show(friends.length);
23. 23.💾 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
24. 24.💾 What number does this code show?
    let coins = 7;
    coins = coins - 7;
    coins = coins + 1;
    show(coins);
25. 25.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Ocean", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Sunrise (c) Kites
26. 26.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) a shared to-do list (d) notes to read offline
27. 27.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
28. 28.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
29. 29.💾 What number does this code show?
    let points = 4;
    points = points - 4;
    points = points + 3;
    show(points);
30. 30.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Zoya", "Aman"];
    show(friends[1]); (a) Aman (b) Zoya (c) Meera
31. 31.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a class leaderboard (d) your last game level
32. 32.💾 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
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.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
35. 35.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a draft you are typing (d) photos on two devices
36. 36.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) a draft you are typing (d) chat messages to friends
37. 37.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Arjun", "Meera", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Zoya (c) Arjun (d) Kabir
38. 38.💾 What number does this code show?
    let stars = 6;
    stars = stars - 2;
    stars = stars + 3;
    show(stars);
39. 39.💾 What number does this code show?
    let score = 5;
    score = score - 1;
    score = score + 2;
    show(score);
40. 40.💾 What number does this code show?
    let coins = 7;
    coins = coins - 5;
    coins = coins + 3;
    show(coins);

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