App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 980 · 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 score = 9;
   score = score - 6;
   score = score + 3;
   show(score);
2. 2.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Music", "Art"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Music (b) Art (c) Maths
3. 3.💾 pop() takes off the last item. What does this code show?
   let songs = ["Kites", "Rain", "Sunrise"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Rain (b) Sunrise (c) Kites
4. 4.💾 What number does this code show?
   let notes = ["Art", "Maths", "Music"];
   notes.push("Hindi");
   show(notes.length);
5. 5.💾 What number does this code show?
   let songs = ["Ocean", "Sunrise"];
   songs.push("Monsoon");
   songs.push("Kites");
   show(songs.length);
6. 6.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
7. 7.💾 What number does this code show?
   let friends = ["Riya", "Kabir", "Zoya", "Aman"];
   friends.push("Meera");
   friends.push("Arjun");
   show(friends.length);
8. 8.💾 Which can hold many values in order? (a) a button (b) a list (c) a single number (d) a switch
9. 9.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
10. 10.💾 What number does this code show?
    let notes = ["Maths", "Art", "Science", "Sports"];
    notes.push("Hindi");
    notes.push("Music");
    show(notes.length);
11. 11.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 2 (c) 1 (d) 0
12. 12.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
13. 13.💾 What number does this code show?
    let stars = 4;
    stars = stars - 4;
    stars = stars + 2;
    show(stars);
14. 14.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Rain", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Sunrise (c) Kites (d) Rain
15. 15.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
16. 16.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Maths", "Music", "Art", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Maths (c) Art (d) Music
17. 17.💾 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
18. 18.Which of these fits saving on the phone? (a) a class leaderboard (b) the sound on/off setting (c) chat messages to friends (d) a shared to-do list
19. 19.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Kites", "Stars", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Kites (d) Monsoon
20. 20.💾 What is a variable? (a) a named box for a value (b) a phone setting (c) a type of screen (d) a picture
21. 21.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) notes to read offline (d) a class leaderboard
22. 22.💾 What number does this code show?
    let score = 4;
    score = score - 2;
    score = score + 5;
    show(score);
23. 23.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
24. 24.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
25. 25.💾 What number does this code show?
    let coins = 7;
    coins = coins - 2;
    coins = coins + 3;
    show(coins);
26. 26.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
27. 27.Which of these fits saving in the cloud? (a) photos on two devices (b) notes to read offline (c) your last game level (d) a draft you are typing
28. 28.True or false: photos on two devices fits saving on the phone. (a) True (b) False
29. 29.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) on the phone (b) in the cloud
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Stars", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Ocean (c) Monsoon
31. 31.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
32. 32.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
33. 33.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Riya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Kabir (c) Aman
34. 34.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
35. 35.💾 What number does this code show?
    let score = 5;
    score = score - 3;
    score = score + 3;
    show(score);
36. 36.💾 What number does this code show?
    let songs = ["Sunrise", "Monsoon"];
    songs.push("Rain");
    songs.push("Stars");
    show(songs.length);
37. 37.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the phone is lost (c) the screen turns off (d) you send a message
38. 38.💾 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
39. 39.💾 What number does this code show?
    let friends = ["Kabir", "Riya", "Arjun"];
    friends.push("Zoya");
    show(friends.length);
40. 40.True or false: your last game level fits saving on the phone. (a) True (b) False

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