App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 15 · 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.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
2. 2.💾 What number does this code show?
   let songs = ["Monsoon", "Kites", "Sunrise"];
   songs.push("Stars");
   show(songs.length);
3. 3.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Meera", "Arjun", "Kabir", "Riya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Kabir (d) Arjun
4. 4.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 2 (c) 0 (d) 1
5. 5.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
6. 6.💾 pop() takes off the last item. What does this code show?
   let friends = ["Riya", "Kabir", "Zoya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Riya
7. 7.Which of these fits saving on the phone? (a) a draft you are typing (b) photos on two devices (c) chat messages to friends (d) a class leaderboard
8. 8.💾 What number does this code show?
   let score = 5;
   score = score - 1;
   score = score + 1;
   show(score);
9. 9.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.💾 What number does this code show?
    let points = 3;
    points = points - 3;
    points = points + 2;
    show(points);
11. 11.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Rain", "Ocean", "Monsoon"];
    show(songs[0]); (a) Monsoon (b) Rain (c) Ocean (d) Stars
12. 12.💾 Which can hold many values in order? (a) a switch (b) a button (c) a single number (d) a list
13. 13.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) shrink the app (d) never need a password
14. 14.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Music", "Maths", "Sports", "Art"];
    show(notes[3]); (a) Sports (b) Maths (c) Science (d) Music
15. 15.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Zoya", "Kabir", "Arjun"];
    show(friends[1]); (a) Kabir (b) Riya (c) Zoya (d) Arjun
16. 16.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
17. 17.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
18. 18.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
19. 19.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) notes to read offline (d) a class leaderboard
20. 20.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Hindi", "Art"];
    show(notes[1]); (a) Hindi (b) Maths (c) Music (d) Art
21. 21.💾 What number does this code show?
    let songs = ["Stars", "Rain", "Ocean"];
    songs.push("Sunrise");
    show(songs.length);
22. 22.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Arjun", "Zoya"];
    show(friends[3]); (a) Arjun (b) Kabir (c) Zoya (d) Meera
23. 23.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
24. 24.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Hindi", "Maths", "Art", "Sports"];
    show(notes[0]); (a) Science (b) Art (c) Maths (d) Hindi
25. 25.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
26. 26.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) photos on two devices (d) notes to read offline
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Monsoon", "Rain", "Ocean", "Stars"];
    show(songs[2]); (a) Monsoon (b) Ocean (c) Sunrise (d) Rain
28. 28.💾 What number does this code show?
    let friends = ["Aman", "Meera", "Zoya", "Arjun"];
    friends.push("Riya");
    friends.push("Kabir");
    show(friends.length);
29. 29.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Art", "Science"];
    show(notes[1]); (a) Art (b) Science (c) Hindi
30. 30.💾 What number does this code show?
    let songs = ["Rain", "Stars", "Monsoon"];
    songs.push("Sunrise");
    show(songs.length);
31. 31.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the app is closed (c) the screen turns off (d) you send a message
32. 32.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Hindi", "Art", "Sports", "Maths"];
    show(notes[0]); (a) Sports (b) Hindi (c) Music (d) Art
33. 33.True or false: notes to read offline fits saving on the phone. (a) False (b) True
34. 34.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Riya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Meera (c) Kabir
35. 35.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
36. 36.💾 What number does this code show?
    let songs = ["Stars", "Sunrise", "Kites", "Rain"];
    songs.push("Monsoon");
    songs.push("Ocean");
    show(songs.length);
37. 37.💾 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
38. 38.💾 What number does this code show?
    let friends = ["Meera", "Riya"];
    friends.push("Aman");
    friends.push("Kabir");
    show(friends.length);
39. 39.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
40. 40.💾 Which works with no internet at all? (a) a cloud backup (b) data saved on the phone (c) a cloud leaderboard (d) a shared chat

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