App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 280 · 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.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) chat messages to friends (d) notes to read offline
2. 2.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
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Monsoon", "Sunrise", "Kites", "Stars", "Rain"];
   show(songs[2]); (a) Monsoon (b) Stars (c) Kites (d) Sunrise
4. 4.💾 What number does this code show?
   let score = 8;
   score = score - 3;
   score = score + 1;
   show(score);
5. 5.💾 pop() takes off the last item. What does this code show?
   let friends = ["Kabir", "Aman", "Meera"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Aman (b) Meera (c) Kabir
6. 6.💾 What number does this code show?
   let points = 4;
   points = points - 2;
   points = points + 3;
   show(points);
7. 7.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
8. 8.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
9. 9.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
10. 10.💾 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
11. 11.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
12. 12.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
13. 13.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Monsoon", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Ocean (c) Monsoon
14. 14.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) never need a password (d) shrink the app
15. 15.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Meera", "Zoya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Meera (c) Kabir (d) Arjun
16. 16.💾 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
17. 17.💾 What number does this code show?
    let lives = 8;
    lives = lives - 6;
    lives = lives + 3;
    show(lives);
18. 18.💾 Which can hold many values in order? (a) a button (b) a switch (c) a list (d) a single number
19. 19.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
20. 20.💾 What is a variable? (a) a type of screen (b) a picture (c) a named box for a value (d) a phone setting
21. 21.💾 What number does this code show?
    let points = 9;
    points = points - 6;
    points = points + 1;
    show(points);
22. 22.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) your last game level (d) photos on two devices
23. 23.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Zoya"];
    show(friends[0]); (a) Zoya (b) Kabir (c) Meera
24. 24.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
25. 25.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Science", "Hindi"];
    show(notes[0]); (a) Science (b) Sports (c) Hindi (d) Maths
26. 26.💾 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
27. 27.💾 What number does this code show?
    let stars = 3;
    stars = stars - 1;
    stars = stars + 1;
    show(stars);
28. 28.True or false: photos on two devices fits saving on the phone. (a) True (b) False
29. 29.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Ocean", "Sunrise", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Sunrise (d) Monsoon
30. 30.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Arjun", "Meera", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Arjun (c) Meera (d) Aman
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Monsoon", "Sunrise"];
    show(songs[1]); (a) Ocean (b) Sunrise (c) Monsoon
32. 32.💾 What number does this code show?
    let songs = ["Rain", "Monsoon"];
    songs.push("Ocean");
    songs.push("Sunrise");
    show(songs.length);
33. 33.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Maths", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Sports (c) Science
34. 34.💾 What number does this code show?
    let score = 3;
    score = score - 2;
    score = score + 4;
    show(score);
35. 35.💾 What number does this code show?
    let score = 6;
    score = score - 2;
    score = score + 2;
    show(score);
36. 36.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
37. 37.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
38. 38.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Aman", "Zoya", "Meera", "Kabir"];
    show(friends[0]); (a) Meera (b) Aman (c) Zoya (d) Arjun
39. 39.💾 What number does this code show?
    let notes = ["Science", "Hindi", "Maths"];
    notes.push("Art");
    show(notes.length);
40. 40.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Arjun", "Aman"];
    show(friends[0]); (a) Arjun (b) Aman (c) Meera

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