App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 185 · 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 coins = 8;
   coins = coins - 6;
   coins = coins + 2;
   show(coins);
2. 2.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) your last game level (d) chat messages to friends
3. 3.💾 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
4. 4.💾 What does this code show? (Positions start at 0.)
   let notes = ["Art", "Maths", "Hindi"];
   show(notes[0]); (a) Hindi (b) Maths (c) Art
5. 5.💾 What does this code show? (Positions start at 0.)
   let friends = ["Zoya", "Arjun", "Aman", "Riya", "Meera"];
   show(friends[0]); (a) Arjun (b) Riya (c) Aman (d) Zoya
6. 6.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 10 (c) 2 (d) 1
7. 7.💾 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
8. 8.💾 What is a variable? (a) a picture (b) a named box for a value (c) a phone setting (d) a type of screen
9. 9.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) chat messages to friends (d) your last game level
10. 10.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Kabir", "Riya", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Riya (c) Arjun (d) Aman
11. 11.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
12. 12.💾 What number does this code show?
    let songs = ["Monsoon", "Ocean", "Kites"];
    songs.push("Stars");
    show(songs.length);
13. 13.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
14. 14.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
15. 15.Which of these fits saving on the phone? (a) notes to read offline (b) a shared to-do list (c) photos on two devices (d) chat messages to friends
16. 16.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
17. 17.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Ocean", "Monsoon", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Ocean (c) Monsoon (d) Rain
18. 18.True or false: your last game level fits saving on the phone. (a) True (b) False
19. 19.💾 What number does this code show?
    let friends = ["Kabir", "Zoya"];
    friends.push("Riya");
    show(friends.length);
20. 20.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Ocean", "Monsoon"];
    show(songs[2]); (a) Monsoon (b) Stars (c) Ocean
21. 21.💾 What number does this code show?
    let coins = 5;
    coins = coins - 5;
    coins = coins + 1;
    show(coins);
22. 22.💾 What number does this code show?
    let lives = 6;
    lives = lives - 6;
    lives = lives + 1;
    show(lives);
23. 23.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Meera", "Kabir"];
    show(friends[0]); (a) Aman (b) Riya (c) Meera (d) Kabir
24. 24.💾 What number does this code show?
    let friends = ["Meera", "Riya"];
    friends.push("Kabir");
    show(friends.length);
25. 25.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
26. 26.💾 Which can hold many values in order? (a) a single number (b) a button (c) a list (d) a switch
27. 27.💾 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
28. 28.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Zoya", "Riya", "Kabir", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Riya (c) Zoya (d) Kabir
29. 29.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a draft you are typing (d) a class leaderboard
30. 30.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
31. 31.💾 What number does this code show?
    let friends = ["Riya", "Arjun"];
    friends.push("Meera");
    friends.push("Kabir");
    show(friends.length);
32. 32.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Art", "Sports", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Sports (c) Hindi (d) Maths
33. 33.True or false: your last game level fits saving in the cloud. (a) True (b) False
34. 34.💾 What number does this code show?
    let songs = ["Kites", "Rain"];
    songs.push("Sunrise");
    songs.push("Monsoon");
    show(songs.length);
35. 35.💾 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
36. 36.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Science", "Maths", "Sports", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Science (c) Maths (d) Hindi
37. 37.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Aman", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Kabir (c) Meera
38. 38.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) a class leaderboard (d) notes to read offline
39. 39.💾 Which works with no internet at all? (a) a shared chat (b) data saved on the phone (c) a cloud backup (d) a cloud leaderboard
40. 40.💾 What number does this code show?
    let friends = ["Kabir", "Arjun"];
    friends.push("Zoya");
    show(friends.length);

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