App Dev Worksheet: Variables, Lists and Saving

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

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