App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 373 · 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 songs = ["Ocean", "Monsoon", "Rain", "Kites"];
   songs.push("Sunrise");
   songs.push("Stars");
   show(songs.length);
2. 2.💾 pop() takes off the last item. What does this code show?
   let notes = ["Art", "Sports", "Hindi", "Music", "Maths"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Music (c) Art (d) Hindi
3. 3.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) a shared to-do list (d) the sound on/off setting
4. 4.True or false: your last game level fits saving in the cloud. (a) False (b) True
5. 5.💾 What number does this code show?
   let lives = 5;
   lives = lives - 4;
   lives = lives + 4;
   show(lives);
6. 6.True or false: notes to read offline fits saving on the phone. (a) True (b) False
7. 7.💾 What number does this code show?
   let songs = ["Ocean", "Rain", "Sunrise", "Stars"];
   songs.push("Monsoon");
   songs.push("Kites");
   show(songs.length);
8. 8.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.💾 What number does this code show?
   let points = 7;
   points = points - 6;
   points = points + 2;
   show(points);
10. 10.💾 What number does this code show?
    let songs = ["Rain", "Stars", "Sunrise"];
    songs.push("Monsoon");
    songs.push("Kites");
    show(songs.length);
11. 11.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
12. 12.💾 Where should the app save a shared to-do list: 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 = ["Stars", "Rain", "Kites", "Sunrise", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Stars (c) Rain (d) Sunrise
14. 14.💾 What number does this code show?
    let points = 8;
    points = points - 2;
    points = points + 5;
    show(points);
15. 15.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
16. 16.💾 What number does this code show?
    let coins = 4;
    coins = coins - 4;
    coins = coins + 5;
    show(coins);
17. 17.Which of these fits saving on the phone? (a) a class leaderboard (b) notes to read offline (c) photos on two devices (d) chat messages to friends
18. 18.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Ocean", "Monsoon", "Kites", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Monsoon (c) Ocean (d) Rain
19. 19.💾 What number does this code show?
    let songs = ["Rain", "Ocean", "Sunrise"];
    songs.push("Stars");
    songs.push("Monsoon");
    show(songs.length);
20. 20.💾 What is a variable? (a) a picture (b) a phone setting (c) a type of screen (d) a named box for a value
21. 21.True or false: photos on two devices fits saving on the phone. (a) True (b) False
22. 22.💾 What number does this code show?
    let notes = ["Hindi", "Sports", "Maths", "Art"];
    notes.push("Science");
    notes.push("Music");
    show(notes.length);
23. 23.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
24. 24.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Monsoon", "Kites", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Kites (c) Rain (d) Monsoon
25. 25.💾 What number does this code show?
    let points = 9;
    points = points - 6;
    points = points + 4;
    show(points);
26. 26.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
27. 27.💾 What number does this code show?
    let points = 3;
    points = points - 1;
    points = points + 4;
    show(points);
28. 28.💾 What number does this code show?
    let notes = ["Maths", "Science", "Music"];
    notes.push("Art");
    notes.push("Hindi");
    show(notes.length);
29. 29.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) chat messages to friends (d) the sound on/off setting
30. 30.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
31. 31.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
32. 32.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) chat messages to friends (d) a draft you are typing
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Science", "Hindi", "Maths", "Art"];
    show(notes[1]); (a) Science (b) Maths (c) Sports (d) Hindi
34. 34.💾 Which works with no internet at all? (a) a shared chat (b) data saved on the phone (c) a cloud leaderboard (d) a cloud backup
35. 35.💾 What number does this code show?
    let notes = ["Science", "Maths"];
    notes.push("Music");
    show(notes.length);
36. 36.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) your last game level (d) a shared to-do list
37. 37.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
38. 38.💾 What number does this code show?
    let songs = ["Sunrise", "Stars", "Monsoon"];
    songs.push("Rain");
    songs.push("Ocean");
    show(songs.length);
39. 39.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
40. 40.True or false: a class leaderboard fits saving on the phone. (a) True (b) False

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