App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 50 · 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 = ["Riya", "Kabir"];
   friends.push("Aman");
   friends.push("Arjun");
   show(friends.length);
2. 2.💾 What number does this code show?
   let coins = 5;
   coins = coins - 3;
   coins = coins + 5;
   show(coins);
3. 3.💾 What number does this code show?
   let songs = ["Stars", "Kites"];
   songs.push("Ocean");
   songs.push("Sunrise");
   show(songs.length);
4. 4.💾 What does this code show? (Positions start at 0.)
   let notes = ["Sports", "Maths", "Hindi"];
   show(notes[2]); (a) Hindi (b) Maths (c) Sports
5. 5.💾 What number does this code show?
   let coins = 4;
   coins = coins - 2;
   coins = coins + 2;
   show(coins);
6. 6.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
7. 7.💾 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
8. 8.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.💾 pop() takes off the last item. What does this code show?
   let songs = ["Rain", "Sunrise", "Stars", "Ocean", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Sunrise (d) Stars
10. 10.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
11. 11.💾 What is a variable? (a) a named box for a value (b) a picture (c) a type of screen (d) a phone setting
12. 12.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Arjun", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Riya (c) Kabir (d) Aman
13. 13.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
14. 14.💾 What number does this code show?
    let coins = 6;
    coins = coins - 5;
    coins = coins + 3;
    show(coins);
15. 15.💾 What number does this code show?
    let notes = ["Science", "Music", "Art", "Maths"];
    notes.push("Hindi");
    notes.push("Sports");
    show(notes.length);
16. 16.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
17. 17.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) never need a password (c) use it on any device (d) shrink the app
18. 18.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
19. 19.💾 Which can hold many values in order? (a) a button (b) a switch (c) a list (d) a single number
20. 20.💾 What number does this code show?
    let notes = ["Music", "Art"];
    notes.push("Science");
    show(notes.length);
21. 21.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
22. 22.💾 What number does this code show?
    let notes = ["Art", "Hindi", "Music"];
    notes.push("Science");
    show(notes.length);
23. 23.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Arjun", "Meera"];
    show(friends[0]); (a) Arjun (b) Riya (c) Meera
24. 24.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Ocean", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Rain (c) Ocean
25. 25.💾 What number does this code show?
    let songs = ["Rain", "Monsoon"];
    songs.push("Ocean");
    show(songs.length);
26. 26.💾 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
27. 27.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
28. 28.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) your last game level (d) a class leaderboard
29. 29.💾 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
30. 30.💾 What number does this code show?
    let notes = ["Maths", "Hindi", "Music"];
    notes.push("Art");
    show(notes.length);
31. 31.💾 What number does this code show?
    let notes = ["Science", "Sports"];
    notes.push("Maths");
    notes.push("Art");
    show(notes.length);
32. 32.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
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Science", "Maths"];
    show(notes[2]); (a) Science (b) Hindi (c) Maths
34. 34.💾 What number does this code show?
    let songs = ["Sunrise", "Rain"];
    songs.push("Kites");
    songs.push("Stars");
    show(songs.length);
35. 35.💾 What number does this code show?
    let notes = ["Art", "Science"];
    notes.push("Music");
    show(notes.length);
36. 36.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the phone is lost (c) the app is closed (d) the screen turns off
37. 37.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Science", "Maths", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Art (d) Science
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Sunrise", "Rain", "Stars", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Rain (c) Sunrise (d) Monsoon
39. 39.Which of these fits saving in the cloud? (a) the sound on/off setting (b) chat messages to friends (c) your last game level (d) a draft you are typing
40. 40.True or false: photos on two devices fits saving in the cloud. (a) False (b) True

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