App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 98 · 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.Which of these fits saving on the phone? (a) photos on two devices (b) the sound on/off setting (c) chat messages to friends (d) a class leaderboard
2. 2.💾 What number does this code show?
   let notes = ["Art", "Hindi", "Science"];
   notes.push("Maths");
   notes.push("Music");
   show(notes.length);
3. 3.💾 What does this code show? (Positions start at 0.)
   let notes = ["Sports", "Music", "Science"];
   show(notes[2]); (a) Music (b) Sports (c) Science
4. 4.💾 What number does this code show?
   let friends = ["Arjun", "Zoya"];
   friends.push("Kabir");
   show(friends.length);
5. 5.💾 What number does this code show?
   let stars = 5;
   stars = stars - 2;
   stars = stars + 2;
   show(stars);
6. 6.💾 pop() takes off the last item. What does this code show?
   let notes = ["Science", "Art", "Music"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Music (b) Science (c) Art
7. 7.💾 What number does this code show?
   let songs = ["Stars", "Kites", "Rain", "Sunrise"];
   songs.push("Monsoon");
   songs.push("Ocean");
   show(songs.length);
8. 8.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the app is closed (c) the phone is lost (d) you send a message
9. 9.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
10. 10.💾 What number does this code show?
    let lives = 3;
    lives = lives - 2;
    lives = lives + 3;
    show(lives);
11. 11.💾 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
12. 12.💾 What number does this code show?
    let songs = ["Sunrise", "Rain", "Stars"];
    songs.push("Ocean");
    songs.push("Monsoon");
    show(songs.length);
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 points = 8;
    points = points - 8;
    points = points + 2;
    show(points);
15. 15.Which of these fits saving in the cloud? (a) chat messages to friends (b) the sound on/off setting (c) a draft you are typing (d) notes to read offline
16. 16.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) notes to read offline (d) a shared to-do list
17. 17.💾 What number does this code show?
    let score = 4;
    score = score - 4;
    score = score + 5;
    show(score);
18. 18.💾 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
19. 19.Which of these fits saving in the cloud? (a) your last game level (b) photos on two devices (c) a draft you are typing (d) notes to read offline
20. 20.True or false: photos on two devices fits saving on the phone. (a) False (b) True
21. 21.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
22. 22.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
23. 23.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a class leaderboard (d) your last game level
24. 24.💾 Which can hold many values in order? (a) a switch (b) a list (c) a single number (d) a button
25. 25.💾 What number does this code show?
    let coins = 4;
    coins = coins - 2;
    coins = coins + 1;
    show(coins);
26. 26.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a draft you are typing (d) chat messages to friends
27. 27.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
28. 28.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Meera", "Aman", "Riya", "Zoya"];
    show(friends[1]); (a) Aman (b) Riya (c) Arjun (d) Meera
29. 29.💾 What number does this code show?
    let notes = ["Science", "Maths", "Art"];
    notes.push("Music");
    notes.push("Sports");
    show(notes.length);
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Science", "Maths", "Art", "Hindi"];
    show(notes[2]); (a) Maths (b) Art (c) Science (d) Sports
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Rain", "Sunrise"];
    show(songs[0]); (a) Rain (b) Stars (c) Sunrise
32. 32.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Aman", "Arjun", "Kabir", "Riya"];
    show(friends[0]); (a) Arjun (b) Zoya (c) Kabir (d) Aman
33. 33.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a picture (d) a type of screen
34. 34.💾 What number does this code show?
    let stars = 5;
    stars = stars - 2;
    stars = stars + 3;
    show(stars);
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Kites", "Rain", "Stars", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Monsoon (d) Stars
36. 36.💾 Which works with no internet at all? (a) data saved on the phone (b) a shared chat (c) a cloud backup (d) a cloud leaderboard
37. 37.💾 What number does this code show?
    let songs = ["Kites", "Ocean", "Stars", "Rain"];
    songs.push("Monsoon");
    songs.push("Sunrise");
    show(songs.length);
38. 38.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) never need a password (c) shrink the app (d) use it on any device
39. 39.True or false: your last game level fits saving in the cloud. (a) True (b) False
40. 40.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone

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