App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 832 · 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 is a variable? (a) a named box for a value (b) a type of screen (c) a phone setting (d) a picture
2. 2.💾 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
3. 3.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
4. 4.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
5. 5.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 0 (d) 1
6. 6.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
7. 7.💾 What number does this code show?
   let notes = ["Maths", "Music", "Sports", "Art"];
   notes.push("Science");
   show(notes.length);
8. 8.💾 What does this code show? (Positions start at 0.)
   let songs = ["Rain", "Sunrise", "Stars"];
   show(songs[2]); (a) Stars (b) Sunrise (c) Rain
9. 9.💾 Which can hold many values in order? (a) a switch (b) a list (c) a single number (d) a button
10. 10.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
11. 11.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Riya", "Zoya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Arjun (c) Zoya (d) Riya
12. 12.Which of these fits saving on the phone? (a) a class leaderboard (b) the sound on/off setting (c) a shared to-do list (d) chat messages to friends
13. 13.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Aman", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Riya (c) Arjun
14. 14.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Rain", "Stars"];
    show(songs[1]); (a) Rain (b) Stars (c) Ocean
15. 15.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
16. 16.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) photos on two devices (d) the sound on/off setting
17. 17.💾 What number does this code show?
    let coins = 6;
    coins = coins - 1;
    coins = coins + 1;
    show(coins);
18. 18.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Rain", "Monsoon", "Sunrise", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Sunrise (c) Rain (d) Monsoon
19. 19.💾 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
20. 20.💾 What number does this code show?
    let lives = 8;
    lives = lives - 8;
    lives = lives + 5;
    show(lives);
21. 21.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a class leaderboard (d) notes to read offline
22. 22.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Monsoon", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Monsoon (c) Ocean
23. 23.💾 What number does this code show?
    let points = 7;
    points = points - 3;
    points = points + 4;
    show(points);
24. 24.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Art", "Music", "Hindi", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Maths (c) Art (d) Hindi
25. 25.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
26. 26.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) notes to read offline (d) a class leaderboard
27. 27.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
28. 28.💾 What number does this code show?
    let songs = ["Kites", "Ocean", "Monsoon", "Sunrise"];
    songs.push("Rain");
    show(songs.length);
29. 29.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Kites", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Kites
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Kites", "Stars", "Monsoon", "Sunrise"];
    show(songs[4]); (a) Ocean (b) Kites (c) Sunrise (d) Stars
32. 32.💾 What number does this code show?
    let friends = ["Meera", "Riya", "Zoya"];
    friends.push("Aman");
    show(friends.length);
33. 33.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the app is closed (c) you send a message (d) the phone is lost
34. 34.True or false: notes to read offline fits saving on the phone. (a) True (b) False
35. 35.💾 What number does this code show?
    let friends = ["Aman", "Meera", "Riya", "Zoya"];
    friends.push("Arjun");
    friends.push("Kabir");
    show(friends.length);
36. 36.True or false: your last game level fits saving on the phone. (a) False (b) True
37. 37.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Kabir", "Arjun", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Riya (c) Kabir (d) Arjun
38. 38.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
39. 39.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Art", "Music", "Hindi", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Art (c) Music (d) Hindi
40. 40.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud

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