App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 413 · 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 songs = ["Rain", "Sunrise"];
   songs.push("Kites");
   show(songs.length);
2. 2.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
3. 3.💾 What number does this code show?
   let notes = ["Maths", "Sports", "Music"];
   notes.push("Hindi");
   show(notes.length);
4. 4.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
5. 5.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
6. 6.💾 What number does this code show?
   let songs = ["Stars", "Sunrise", "Rain"];
   songs.push("Ocean");
   show(songs.length);
7. 7.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a shared to-do list (d) notes to read offline
8. 8.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
9. 9.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Ocean"];
    show(songs[1]); (a) Ocean (b) Monsoon (c) Kites
11. 11.💾 What number does this code show?
    let stars = 3;
    stars = stars - 2;
    stars = stars + 5;
    show(stars);
12. 12.💾 What number does this code show?
    let friends = ["Zoya", "Meera", "Aman", "Arjun"];
    friends.push("Riya");
    show(friends.length);
13. 13.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Zoya", "Arjun", "Meera", "Riya"];
    show(friends[3]); (a) Kabir (b) Arjun (c) Meera (d) Zoya
14. 14.True or false: your last game level fits saving on the phone. (a) False (b) True
15. 15.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
16. 16.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Kites"];
    show(songs[2]); (a) Monsoon (b) Rain (c) Kites
17. 17.💾 Which can hold many values in order? (a) a single number (b) a switch (c) a button (d) a list
18. 18.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud leaderboard (c) a cloud backup (d) a shared chat
19. 19.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Art", "Music", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Art (c) Maths (d) Music
20. 20.💾 What number does this code show?
    let songs = ["Kites", "Stars"];
    songs.push("Ocean");
    songs.push("Monsoon");
    show(songs.length);
21. 21.💾 What number does this code show?
    let songs = ["Monsoon", "Ocean", "Rain"];
    songs.push("Kites");
    show(songs.length);
22. 22.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
23. 23.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) you send a message (d) the phone is lost
24. 24.💾 What is a variable? (a) a picture (b) a phone setting (c) a named box for a value (d) a type of screen
25. 25.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 2 (d) 0
26. 26.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
27. 27.💾 What number does this code show?
    let stars = 4;
    stars = stars - 1;
    stars = stars + 3;
    show(stars);
28. 28.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Stars", "Ocean", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Rain (d) Ocean
29. 29.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Music", "Sports", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Hindi (c) Sports (d) Music
30. 30.💾 What number does this code show?
    let friends = ["Riya", "Aman", "Zoya"];
    friends.push("Arjun");
    friends.push("Kabir");
    show(friends.length);
31. 31.💾 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
32. 32.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) a shared to-do list (d) the sound on/off setting
33. 33.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
34. 34.💾 What number does this code show?
    let coins = 3;
    coins = coins - 2;
    coins = coins + 4;
    show(coins);
35. 35.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Ocean"];
    show(songs[1]); (a) Kites (b) Ocean (c) Sunrise
36. 36.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) chat messages to friends (d) a draft you are typing
37. 37.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a shared to-do list (d) your last game level
38. 38.💾 What number does this code show?
    let friends = ["Meera", "Arjun"];
    friends.push("Riya");
    show(friends.length);
39. 39.💾 What number does this code show?
    let songs = ["Rain", "Stars", "Ocean", "Sunrise"];
    songs.push("Monsoon");
    songs.push("Kites");
    show(songs.length);
40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Rain", "Stars", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Ocean (c) Rain (d) Stars

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