App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 342 · 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 lives = 6;
   lives = lives - 4;
   lives = lives + 1;
   show(lives);
2. 2.💾 What does this code show? (Positions start at 0.)
   let songs = ["Sunrise", "Monsoon", "Rain"];
   show(songs[1]); (a) Sunrise (b) Rain (c) Monsoon
3. 3.💾 Which can hold many values in order? (a) a list (b) a button (c) a single number (d) a switch
4. 4.💾 What does this code show? (Positions start at 0.)
   let friends = ["Arjun", "Riya", "Aman"];
   show(friends[1]); (a) Aman (b) Riya (c) Arjun
5. 5.Which of these fits saving on the phone? (a) photos on two devices (b) the sound on/off setting (c) a class leaderboard (d) chat messages to friends
6. 6.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
7. 7.💾 What does this code show? (Positions start at 0.)
   let notes = ["Art", "Music", "Science", "Sports", "Maths"];
   show(notes[0]); (a) Art (b) Science (c) Music (d) Sports
8. 8.💾 pop() takes off the last item. What does this code show?
   let friends = ["Meera", "Aman", "Zoya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Meera (b) Zoya (c) Aman
9. 9.💾 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
10. 10.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) the sound on/off setting (d) a shared to-do list
11. 11.Which of these fits saving on the phone? (a) chat messages to friends (b) a shared to-do list (c) your last game level (d) photos on two devices
12. 12.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the phone is lost (c) the screen turns off (d) the app is closed
13. 13.💾 What number does this code show?
    let stars = 7;
    stars = stars - 7;
    stars = stars + 5;
    show(stars);
14. 14.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Stars", "Sunrise", "Monsoon", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Monsoon (d) Ocean
15. 15.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
16. 16.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
17. 17.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
18. 18.💾 What number does this code show?
    let notes = ["Art", "Sports", "Science"];
    notes.push("Maths");
    notes.push("Hindi");
    show(notes.length);
19. 19.💾 What number does this code show?
    let notes = ["Art", "Science", "Hindi", "Music"];
    notes.push("Maths");
    show(notes.length);
20. 20.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Aman", "Kabir", "Riya"];
    show(friends[2]); (a) Arjun (b) Riya (c) Kabir (d) Aman
21. 21.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
22. 22.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Science", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Music (c) Sports
23. 23.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 1 (d) 2
24. 24.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) skip the internet (c) shrink the app (d) never need a password
25. 25.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Aman", "Riya", "Zoya"];
    show(friends[1]); (a) Aman (b) Riya (c) Meera (d) Kabir
26. 26.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
27. 27.True or false: notes to read offline fits saving on the phone. (a) False (b) True
28. 28.💾 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
29. 29.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Aman", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Aman (c) Zoya
30. 30.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) photos on two devices (d) notes to read offline
31. 31.💾 What number does this code show?
    let score = 4;
    score = score - 2;
    score = score + 1;
    show(score);
32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Kabir", "Zoya", "Arjun", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Arjun (c) Zoya (d) Riya
33. 33.💾 What number does this code show?
    let notes = ["Hindi", "Science", "Maths"];
    notes.push("Art");
    show(notes.length);
34. 34.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Music", "Art", "Science"];
    show(notes[0]); (a) Sports (b) Music (c) Art (d) Maths
35. 35.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
36. 36.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
37. 37.True or false: photos on two devices fits saving on the phone. (a) False (b) True
38. 38.💾 What number does this code show?
    let songs = ["Sunrise", "Ocean", "Stars"];
    songs.push("Rain");
    songs.push("Kites");
    show(songs.length);
39. 39.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Stars", "Rain", "Sunrise"];
    show(songs[0]); (a) Sunrise (b) Monsoon (c) Rain (d) Stars
40. 40.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud

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