App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 199 · 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 = 7;
   lives = lives - 4;
   lives = lives + 1;
   show(lives);
2. 2.💾 What does this code show? (Positions start at 0.)
   let notes = ["Science", "Sports", "Maths"];
   show(notes[0]); (a) Maths (b) Science (c) Sports
3. 3.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
4. 4.💾 What number does this code show?
   let coins = 8;
   coins = coins - 1;
   coins = coins + 4;
   show(coins);
5. 5.💾 pop() takes off the last item. What does this code show?
   let songs = ["Ocean", "Rain", "Sunrise", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Ocean (b) Kites (c) Sunrise (d) Rain
6. 6.💾 What number does this code show?
   let stars = 8;
   stars = stars - 7;
   stars = stars + 1;
   show(stars);
7. 7.Which of these fits saving on the phone? (a) a shared to-do list (b) notes to read offline (c) photos on two devices (d) chat messages to friends
8. 8.💾 What number does this code show?
   let stars = 4;
   stars = stars - 2;
   stars = stars + 4;
   show(stars);
9. 9.💾 Which can hold many values in order? (a) a list (b) a button (c) a single number (d) a switch
10. 10.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
11. 11.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) a class leaderboard (d) the sound on/off setting
12. 12.💾 Which works with no internet at all? (a) data saved on the phone (b) a shared chat (c) a cloud leaderboard (d) a cloud backup
13. 13.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Sports", "Music", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Music (c) Hindi (d) Sports
14. 14.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
15. 15.💾 What number does this code show?
    let notes = ["Art", "Music", "Maths", "Hindi"];
    notes.push("Sports");
    notes.push("Science");
    show(notes.length);
16. 16.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
17. 17.True or false: notes to read offline fits saving on the phone. (a) True (b) False
18. 18.Which of these fits saving in the cloud? (a) notes to read offline (b) chat messages to friends (c) a draft you are typing (d) the sound on/off setting
19. 19.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Rain", "Kites", "Stars", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Kites (c) Stars (d) Rain
20. 20.Which of these fits saving on the phone? (a) a class leaderboard (b) a draft you are typing (c) a shared to-do list (d) photos on two devices
21. 21.💾 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
22. 22.💾 What number does this code show?
    let friends = ["Aman", "Kabir", "Arjun"];
    friends.push("Riya");
    friends.push("Meera");
    show(friends.length);
23. 23.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Art", "Science", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Hindi (c) Science (d) Art
24. 24.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Sports", "Art", "Science"];
    show(notes[1]); (a) Sports (b) Hindi (c) Art (d) Science
25. 25.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
26. 26.💾 What number does this code show?
    let stars = 6;
    stars = stars - 1;
    stars = stars + 1;
    show(stars);
27. 27.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
28. 28.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) photos on two devices (d) your last game level
29. 29.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Science", "Music"];
    show(notes[3]); (a) Art (b) Science (c) Music (d) Maths
30. 30.💾 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
31. 31.💾 What number does this code show?
    let notes = ["Art", "Science", "Music"];
    notes.push("Maths");
    notes.push("Hindi");
    show(notes.length);
32. 32.True or false: your last game level fits saving on the phone. (a) False (b) True
33. 33.True or false: photos on two devices fits saving on the phone. (a) False (b) True
34. 34.💾 What number does this code show?
    let songs = ["Ocean", "Rain", "Monsoon"];
    songs.push("Stars");
    show(songs.length);
35. 35.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Kabir", "Arjun", "Riya", "Zoya"];
    show(friends[1]); (a) Meera (b) Kabir (c) Arjun (d) Riya
36. 36.💾 What number does this code show?
    let notes = ["Art", "Science"];
    notes.push("Music");
    notes.push("Hindi");
    show(notes.length);
37. 37.💾 What is a variable? (a) a picture (b) a phone setting (c) a type of screen (d) a named box for a value
38. 38.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Kabir", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Riya
39. 39.💾 Where should the app save notes to read offline: 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 notes = ["Art", "Music", "Sports", "Science", "Maths"];
    show(notes[3]); (a) Sports (b) Music (c) Science (d) Art

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