App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 720 · 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 friends = ["Aman", "Kabir", "Zoya"];
   friends.push("Arjun");
   friends.push("Meera");
   show(friends.length);
2. 2.Which of these fits saving on the phone? (a) photos on two devices (b) notes to read offline (c) a class leaderboard (d) chat messages to friends
3. 3.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) your last game level (d) photos on two devices
4. 4.Which of these fits saving on the phone? (a) a draft you are typing (b) a shared to-do list (c) a class leaderboard (d) photos on two devices
5. 5.💾 What number does this code show?
   let songs = ["Stars", "Rain"];
   songs.push("Sunrise");
   songs.push("Monsoon");
   show(songs.length);
6. 6.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a shared to-do list (d) a draft you are typing
8. 8.True or false: photos on two devices fits saving on the phone. (a) False (b) True
9. 9.💾 Which can hold many values in order? (a) a button (b) a single number (c) a list (d) a switch
10. 10.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) a class leaderboard (d) the sound on/off setting
11. 11.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
12. 12.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
13. 13.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) your last game level
14. 14.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
15. 15.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
16. 16.True or false: notes to read offline fits saving on the phone. (a) False (b) True
17. 17.💾 What number does this code show?
    let score = 9;
    score = score - 1;
    score = score + 2;
    show(score);
18. 18.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 3;
    show(score);
19. 19.💾 Saving data in the cloud lets you ___. (a) never need a password (b) skip the internet (c) shrink the app (d) use it on any device
20. 20.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
21. 21.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Maths", "Hindi", "Science", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Science (c) Maths (d) Sports
22. 22.💾 What number does this code show?
    let notes = ["Sports", "Music", "Maths"];
    notes.push("Hindi");
    show(notes.length);
23. 23.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
24. 24.💾 Which works with no internet at all? (a) a shared chat (b) a cloud leaderboard (c) data saved on the phone (d) a cloud backup
25. 25.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Maths (c) Hindi
26. 26.💾 What is a variable? (a) a phone setting (b) a picture (c) a named box for a value (d) a type of screen
27. 27.💾 What number does this code show?
    let friends = ["Kabir", "Zoya"];
    friends.push("Meera");
    friends.push("Riya");
    show(friends.length);
28. 28.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the phone is lost (d) the screen turns off
29. 29.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
30. 30.💾 What number does this code show?
    let notes = ["Science", "Sports", "Hindi", "Art"];
    notes.push("Music");
    show(notes.length);
31. 31.💾 What number does this code show?
    let score = 7;
    score = score - 2;
    score = score + 3;
    show(score);
32. 32.Which of these fits saving on the phone? (a) the sound on/off setting (b) a shared to-do list (c) photos on two devices (d) a class leaderboard
33. 33.💾 What number does this code show?
    let notes = ["Science", "Art"];
    notes.push("Maths");
    show(notes.length);
34. 34.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
35. 35.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Meera", "Aman"];
    show(friends[2]); (a) Zoya (b) Aman (c) Meera
36. 36.💾 What number does this code show?
    let notes = ["Art", "Science", "Maths", "Hindi"];
    notes.push("Music");
    show(notes.length);
37. 37.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
38. 38.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Art", "Science", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Art (c) Hindi (d) Science
39. 39.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
40. 40.True or false: a draft you are typing fits saving on the phone. (a) True (b) False

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