App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 616 · 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 score = 6;
   score = score - 3;
   score = score + 5;
   show(score);
2. 2.💾 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
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.💾 pop() takes off the last item. What does this code show?
   let songs = ["Kites", "Rain", "Ocean"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Ocean
5. 5.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
6. 6.💾 Which can hold many values in order? (a) a switch (b) a button (c) a single number (d) a list
7. 7.Which of these fits saving on the phone? (a) photos on two devices (b) notes to read offline (c) a shared to-do list (d) chat messages to friends
8. 8.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
9. 9.💾 What number does this code show?
   let songs = ["Stars", "Rain"];
   songs.push("Kites");
   songs.push("Monsoon");
   show(songs.length);
10. 10.💾 What number does this code show?
    let songs = ["Stars", "Monsoon"];
    songs.push("Sunrise");
    show(songs.length);
11. 11.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) notes to read offline (d) chat messages to friends
12. 12.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
13. 13.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
14. 14.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
15. 15.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
16. 16.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Hindi", "Maths", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Science (d) Maths
17. 17.💾 What number does this code show?
    let friends = ["Kabir", "Riya"];
    friends.push("Meera");
    friends.push("Zoya");
    show(friends.length);
18. 18.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Riya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Riya (c) Meera
19. 19.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
20. 20.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Aman", "Kabir", "Riya", "Arjun"];
    show(friends[0]); (a) Riya (b) Kabir (c) Aman (d) Meera
21. 21.💾 What number does this code show?
    let friends = ["Arjun", "Aman", "Zoya"];
    friends.push("Kabir");
    friends.push("Riya");
    show(friends.length);
22. 22.True or false: your last game level fits saving on the phone. (a) False (b) True
23. 23.💾 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
24. 24.💾 What number does this code show?
    let lives = 8;
    lives = lives - 2;
    lives = lives + 3;
    show(lives);
25. 25.💾 What number does this code show?
    let songs = ["Sunrise", "Monsoon", "Stars", "Kites"];
    songs.push("Rain");
    show(songs.length);
26. 26.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 1 (d) 10
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Stars", "Ocean", "Sunrise", "Rain"];
    show(songs[4]); (a) Rain (b) Ocean (c) Stars (d) Monsoon
28. 28.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 4;
    show(score);
29. 29.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the screen turns off (c) the phone is lost (d) the app is closed
30. 30.💾 What number does this code show?
    let points = 5;
    points = points - 3;
    points = points + 4;
    show(points);
31. 31.💾 What is a variable? (a) a picture (b) a phone setting (c) a type of screen (d) a named box for a value
32. 32.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
33. 33.💾 What number does this code show?
    let friends = ["Kabir", "Riya", "Aman", "Zoya"];
    friends.push("Arjun");
    show(friends.length);
34. 34.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Rain", "Sunrise", "Stars", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Sunrise (c) Stars (d) Monsoon
36. 36.Which of these fits saving in the cloud? (a) photos on two devices (b) notes to read offline (c) a draft you are typing (d) the sound on/off setting
37. 37.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
38. 38.💾 What number does this code show?
    let points = 7;
    points = points - 6;
    points = points + 4;
    show(points);
39. 39.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Arjun", "Riya", "Meera"];
    show(friends[2]); (a) Aman (b) Meera (c) Riya (d) Arjun
40. 40.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Sunrise", "Rain", "Stars"];
    show(songs[1]); (a) Kites (b) Rain (c) Sunrise (d) Monsoon

Free app development lessons, practice and worksheets at talentjr.in/app-development-for-students