App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 291 · 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 in the cloud? (a) notes to read offline (b) your last game level (c) the sound on/off setting (d) a class leaderboard
2. 2.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
3. 3.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 0 (d) 10
4. 4.💾 What is a variable? (a) a picture (b) a type of screen (c) a named box for a value (d) a phone setting
5. 5.💾 pop() takes off the last item. What does this code show?
   let songs = ["Rain", "Sunrise", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Rain
6. 6.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
7. 7.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the screen turns off (c) the app is closed (d) you send a message
8. 8.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
9. 9.True or false: notes to read offline fits saving on the phone. (a) True (b) False
10. 10.💾 What number does this code show?
    let points = 8;
    points = points - 6;
    points = points + 1;
    show(points);
11. 11.💾 What number does this code show?
    let score = 8;
    score = score - 6;
    score = score + 3;
    show(score);
12. 12.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
13. 13.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Riya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Riya (c) Aman
14. 14.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) a shared to-do list (d) notes to read offline
15. 15.💾 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
16. 16.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
17. 17.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
18. 18.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
19. 19.💾 What number does this code show?
    let notes = ["Art", "Music"];
    notes.push("Maths");
    show(notes.length);
20. 20.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
21. 21.💾 What number does this code show?
    let songs = ["Ocean", "Kites"];
    songs.push("Sunrise");
    songs.push("Rain");
    show(songs.length);
22. 22.True or false: photos on two devices fits saving on the phone. (a) False (b) True
23. 23.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a class leaderboard (d) your last game level
24. 24.💾 What number does this code show?
    let lives = 4;
    lives = lives - 4;
    lives = lives + 2;
    show(lives);
25. 25.💾 What number does this code show?
    let points = 4;
    points = points - 4;
    points = points + 2;
    show(points);
26. 26.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
27. 27.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Kites", "Rain", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Sunrise (c) Rain (d) Kites
28. 28.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.💾 What number does this code show?
    let songs = ["Stars", "Kites", "Ocean", "Monsoon"];
    songs.push("Rain");
    show(songs.length);
30. 30.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) use it on any device (d) never need a password
31. 31.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) the sound on/off setting (d) a class leaderboard
32. 32.💾 What number does this code show?
    let songs = ["Kites", "Stars", "Rain", "Monsoon"];
    songs.push("Sunrise");
    songs.push("Ocean");
    show(songs.length);
33. 33.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 2;
    show(score);
34. 34.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
35. 35.💾 What number does this code show?
    let lives = 5;
    lives = lives - 2;
    lives = lives + 1;
    show(lives);
36. 36.💾 What number does this code show?
    let songs = ["Stars", "Monsoon", "Rain", "Kites"];
    songs.push("Ocean");
    show(songs.length);
37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Science"];
    show(notes[2]); (a) Maths (b) Science (c) Music
38. 38.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Hindi", "Sports", "Maths", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Music (c) Maths (d) Sports
39. 39.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Kabir", "Aman", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Aman (c) Arjun (d) Meera
40. 40.💾 What number does this code show?
    let lives = 7;
    lives = lives - 7;
    lives = lives + 2;
    show(lives);

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