App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 900 · 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 points = 9;
   points = points - 5;
   points = points + 2;
   show(points);
2. 2.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
3. 3.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
4. 4.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a class leaderboard (d) the sound on/off setting
5. 5.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud leaderboard (c) a shared chat (d) a cloud backup
6. 6.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.True or false: your last game level fits saving in the cloud. (a) False (b) True
8. 8.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
9. 9.💾 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
10. 10.💾 What is a variable? (a) a named box for a value (b) a picture (c) a phone setting (d) a type of screen
11. 11.💾 What number does this code show?
    let lives = 7;
    lives = lives - 2;
    lives = lives + 5;
    show(lives);
12. 12.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) chat messages to friends (d) your last game level
13. 13.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a class leaderboard (d) notes to read offline
14. 14.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) shrink the app (c) skip the internet (d) never need a password
15. 15.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Art", "Music", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Maths (c) Music (d) Art
16. 16.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
17. 17.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Ocean", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Ocean (c) Sunrise
18. 18.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
19. 19.💾 What number does this code show?
    let friends = ["Arjun", "Aman"];
    friends.push("Meera");
    show(friends.length);
20. 20.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 10 (c) 1 (d) 2
21. 21.True or false: notes to read offline fits saving on the phone. (a) False (b) True
22. 22.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
23. 23.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) photos on two devices (d) a draft you are typing
24. 24.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
25. 25.💾 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
26. 26.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Meera", "Arjun", "Zoya", "Riya"];
    show(friends[2]); (a) Zoya (b) Meera (c) Aman (d) Arjun
27. 27.💾 What number does this code show?
    let notes = ["Maths", "Music", "Art"];
    notes.push("Sports");
    show(notes.length);
28. 28.Which of these fits saving on the phone? (a) photos on two devices (b) a draft you are typing (c) a class leaderboard (d) chat messages to friends
29. 29.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
30. 30.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Riya", "Zoya"];
    show(friends[0]); (a) Kabir (b) Riya (c) Zoya
31. 31.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
32. 32.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Sports", "Music", "Hindi", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Music (c) Hindi (d) Maths
33. 33.💾 What number does this code show?
    let coins = 4;
    coins = coins - 1;
    coins = coins + 3;
    show(coins);
34. 34.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
35. 35.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
36. 36.💾 What number does this code show?
    let notes = ["Art", "Music", "Sports", "Maths"];
    notes.push("Science");
    notes.push("Hindi");
    show(notes.length);
37. 37.Which of these fits saving in the cloud? (a) your last game level (b) chat messages to friends (c) the sound on/off setting (d) notes to read offline
38. 38.💾 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
39. 39.💾 What number does this code show?
    let stars = 5;
    stars = stars - 3;
    stars = stars + 2;
    show(stars);
40. 40.💾 What number does this code show?
    let stars = 7;
    stars = stars - 7;
    stars = stars + 2;
    show(stars);

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