App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 64 · 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 notes = ["Music", "Science", "Hindi", "Maths"];
   notes.push("Art");
   notes.push("Sports");
   show(notes.length);
2. 2.💾 pop() takes off the last item. What does this code show?
   let songs = ["Rain", "Stars", "Ocean", "Kites", "Monsoon"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Rain (b) Stars (c) Ocean (d) Kites
3. 3.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.True or false: your last game level fits saving on the phone. (a) False (b) True
5. 5.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
6. 6.💾 pop() takes off the last item. What does this code show?
   let friends = ["Zoya", "Aman", "Kabir"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Zoya (b) Aman (c) Kabir
7. 7.Which of these fits saving on the phone? (a) a draft you are typing (b) a shared to-do list (c) photos on two devices (d) chat messages to friends
8. 8.💾 What number does this code show?
   let coins = 4;
   coins = coins - 4;
   coins = coins + 3;
   show(coins);
9. 9.💾 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
10. 10.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Monsoon", "Sunrise", "Ocean"];
    show(songs[0]); (a) Rain (b) Sunrise (c) Monsoon (d) Ocean
11. 11.Which of these fits saving on the phone? (a) chat messages to friends (b) notes to read offline (c) a shared to-do list (d) photos on two devices
12. 12.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Arjun", "Kabir", "Zoya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Riya (c) Arjun (d) Kabir
13. 13.💾 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
14. 14.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) a draft you are typing (d) a shared to-do list
15. 15.💾 Which can hold many values in order? (a) a button (b) a list (c) a single number (d) a switch
16. 16.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 0 (d) 1
17. 17.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
18. 18.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
19. 19.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Meera", "Aman", "Zoya", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Aman (c) Meera (d) Zoya
20. 20.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) use it on any device (d) skip the internet
21. 21.💾 What number does this code show?
    let score = 5;
    score = score - 3;
    score = score + 3;
    show(score);
22. 22.💾 What number does this code show?
    let notes = ["Sports", "Music", "Science"];
    notes.push("Hindi");
    notes.push("Maths");
    show(notes.length);
23. 23.💾 What is a variable? (a) a picture (b) a type of screen (c) a phone setting (d) a named box for a value
24. 24.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
25. 25.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Stars", "Sunrise"];
    show(songs[0]); (a) Stars (b) Monsoon (c) Sunrise
26. 26.True or false: notes to read offline fits saving on the phone. (a) True (b) False
27. 27.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
28. 28.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
29. 29.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Kites", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Stars (c) Monsoon
31. 31.💾 What number does this code show?
    let notes = ["Hindi", "Art", "Maths"];
    notes.push("Science");
    notes.push("Sports");
    show(notes.length);
32. 32.💾 What number does this code show?
    let coins = 4;
    coins = coins - 4;
    coins = coins + 1;
    show(coins);
33. 33.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Aman", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Meera (c) Aman (d) Kabir
34. 34.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) notes to read offline (d) chat messages to friends
35. 35.💾 What number does this code show?
    let score = 3;
    score = score - 2;
    score = score + 1;
    show(score);
36. 36.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Monsoon", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Monsoon
37. 37.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
38. 38.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
39. 39.Which of these fits saving in the cloud? (a) photos on two devices (b) your last game level (c) a draft you are typing (d) notes to read offline
40. 40.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Maths", "Sports", "Music", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Music (c) Sports (d) Maths

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