App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 273 · 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 draft you are typing (b) a class leaderboard (c) photos on two devices (d) a shared to-do list
2. 2.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
3. 3.💾 Which can hold many values in order? (a) a single number (b) a list (c) a switch (d) a button
4. 4.💾 What does this code show? (Positions start at 0.)
   let notes = ["Art", "Science", "Music"];
   show(notes[2]); (a) Science (b) Art (c) Music
5. 5.💾 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
6. 6.💾 What number does this code show?
   let songs = ["Kites", "Ocean", "Rain"];
   songs.push("Monsoon");
   songs.push("Stars");
   show(songs.length);
7. 7.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the app is closed (c) the screen turns off (d) the phone is lost
8. 8.💾 What number does this code show?
   let songs = ["Monsoon", "Stars", "Rain"];
   songs.push("Kites");
   show(songs.length);
9. 9.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Maths", "Sports", "Hindi", "Art"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Hindi (d) Music
10. 10.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) shrink the app (c) skip the internet (d) never need a password
11. 11.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) chat messages to friends (d) notes to read offline
12. 12.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Sunrise", "Ocean", "Monsoon"];
    show(songs[1]); (a) Sunrise (b) Ocean (c) Monsoon (d) Rain
13. 13.💾 Which works with no internet at all? (a) a shared chat (b) a cloud backup (c) a cloud leaderboard (d) data saved on the phone
14. 14.💾 What number does this code show?
    let songs = ["Rain", "Monsoon", "Stars", "Ocean"];
    songs.push("Kites");
    show(songs.length);
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Sports"];
    show(notes[0]); (a) Sports (b) Art (c) Music
16. 16.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
17. 17.💾 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
18. 18.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Kites", "Rain", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Ocean (c) Sunrise (d) Kites
19. 19.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
20. 20.Which of these fits saving in the cloud? (a) a class leaderboard (b) the sound on/off setting (c) notes to read offline (d) a draft you are typing
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Zoya", "Meera", "Arjun"];
    show(friends[1]); (a) Meera (b) Aman (c) Riya (d) Zoya
22. 22.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
23. 23.💾 What number does this code show?
    let score = 5;
    score = score - 3;
    score = score + 2;
    show(score);
24. 24.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
25. 25.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
26. 26.💾 What number does this code show?
    let friends = ["Zoya", "Riya", "Meera", "Arjun"];
    friends.push("Aman");
    show(friends.length);
27. 27.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
28. 28.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Music", "Hindi", "Art", "Maths"];
    show(notes[3]); (a) Science (b) Music (c) Hindi (d) Art
29. 29.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Rain"];
    show(songs[2]); (a) Kites (b) Rain (c) Sunrise
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Hindi", "Art", "Maths"];
    show(notes[0]); (a) Maths (b) Hindi (c) Sports (d) Art
31. 31.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 3;
    show(coins);
32. 32.💾 What number does this code show?
    let lives = 5;
    lives = lives - 1;
    lives = lives + 3;
    show(lives);
33. 33.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) photos on two devices (d) the sound on/off setting
34. 34.💾 What number does this code show?
    let notes = ["Maths", "Art", "Hindi", "Sports"];
    notes.push("Science");
    notes.push("Music");
    show(notes.length);
35. 35.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
36. 36.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Science", "Maths", "Music"];
    show(notes[2]); (a) Hindi (b) Maths (c) Science (d) Art
37. 37.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
38. 38.💾 What is a variable? (a) a type of screen (b) a phone setting (c) a picture (d) a named box for a value
39. 39.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Kabir", "Meera", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Meera (c) Riya (d) Kabir
40. 40.💾 What number does this code show?
    let friends = ["Zoya", "Kabir", "Riya"];
    friends.push("Arjun");
    show(friends.length);

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