App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 233 · 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 lives = 4;
   lives = lives - 2;
   lives = lives + 1;
   show(lives);
2. 2.💾 What number does this code show?
   let friends = ["Arjun", "Riya"];
   friends.push("Aman");
   show(friends.length);
3. 3.💾 Where should the app save notes to read offline: 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 friends = ["Riya", "Arjun", "Meera", "Aman", "Zoya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Arjun (b) Aman (c) Meera (d) Riya
5. 5.💾 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
6. 6.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) data saved on the phone (d) a shared chat
7. 7.True or false: your last game level fits saving on the phone. (a) False (b) True
8. 8.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) a draft you are typing
9. 9.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
10. 10.💾 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
11. 11.💾 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
12. 12.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a shared to-do list (d) notes to read offline
13. 13.💾 What number does this code show?
    let points = 5;
    points = points - 2;
    points = points + 4;
    show(points);
14. 14.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) a shared to-do list (d) notes to read offline
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Sports", "Maths", "Hindi"];
    show(notes[2]); (a) Sports (b) Hindi (c) Science (d) Maths
16. 16.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
17. 17.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a class leaderboard (d) your last game level
18. 18.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
19. 19.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
20. 20.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) photos on two devices (d) your last game level
21. 21.💾 What number does this code show?
    let notes = ["Hindi", "Maths", "Sports"];
    notes.push("Science");
    notes.push("Music");
    show(notes.length);
22. 22.💾 What number does this code show?
    let score = 4;
    score = score - 1;
    score = score + 2;
    show(score);
23. 23.💾 What number does this code show?
    let coins = 4;
    coins = coins - 1;
    coins = coins + 5;
    show(coins);
24. 24.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the app is closed (c) the screen turns off (d) you send a message
25. 25.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Stars", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Ocean (c) Stars
26. 26.💾 What is a variable? (a) a named box for a value (b) a picture (c) a type of screen (d) a phone setting
27. 27.💾 What number does this code show?
    let friends = ["Arjun", "Meera", "Kabir"];
    friends.push("Riya");
    show(friends.length);
28. 28.💾 What number does this code show?
    let coins = 4;
    coins = coins - 1;
    coins = coins + 2;
    show(coins);
29. 29.💾 What number does this code show?
    let score = 6;
    score = score - 2;
    score = score + 2;
    show(score);
30. 30.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
31. 31.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 2 (d) 10
32. 32.True or false: photos on two devices fits saving on the phone. (a) True (b) False
33. 33.💾 What number does this code show?
    let friends = ["Riya", "Aman"];
    friends.push("Zoya");
    show(friends.length);
34. 34.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Sports", "Music", "Maths", "Art"];
    show(notes[0]); (a) Maths (b) Sports (c) Science (d) Music
35. 35.💾 What number does this code show?
    let coins = 9;
    coins = coins - 1;
    coins = coins + 1;
    show(coins);
36. 36.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
37. 37.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a shared to-do list (d) your last game level
38. 38.💾 What number does this code show?
    let lives = 5;
    lives = lives - 4;
    lives = lives + 5;
    show(lives);
39. 39.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
40. 40.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Riya", "Arjun", "Aman", "Zoya"];
    show(friends[3]); (a) Riya (b) Arjun (c) Aman (d) Meera

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