App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 365 · 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 = ["Kites", "Monsoon", "Sunrise"];
   songs.push("Ocean");
   songs.push("Rain");
   show(songs.length);
2. 2.💾 What is a variable? (a) a picture (b) a type of screen (c) a phone setting (d) a named box for a value
3. 3.💾 What number does this code show?
   let coins = 8;
   coins = coins - 5;
   coins = coins + 2;
   show(coins);
4. 4.💾 pop() takes off the last item. What does this code show?
   let friends = ["Meera", "Kabir", "Arjun", "Aman", "Riya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Aman (b) Meera (c) Arjun (d) Kabir
5. 5.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.💾 What does this code show? (Positions start at 0.)
   let friends = ["Arjun", "Riya", "Kabir", "Zoya", "Meera"];
   show(friends[0]); (a) Zoya (b) Kabir (c) Riya (d) Arjun
7. 7.💾 What does this code show? (Positions start at 0.)
   let friends = ["Zoya", "Kabir", "Riya", "Arjun"];
   show(friends[2]); (a) Kabir (b) Riya (c) Zoya (d) Arjun
8. 8.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) the sound on/off setting (d) a shared to-do list
9. 9.💾 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
10. 10.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Meera", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Arjun (c) Meera
11. 11.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.💾 What number does this code show?
    let songs = ["Rain", "Stars"];
    songs.push("Sunrise");
    show(songs.length);
13. 13.💾 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
14. 14.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the phone is lost (c) the app is closed (d) you send a message
15. 15.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) chat messages to friends (d) your last game level
16. 16.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Hindi", "Music", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Music (c) Art (d) Science
17. 17.💾 What number does this code show?
    let lives = 3;
    lives = lives - 2;
    lives = lives + 1;
    show(lives);
18. 18.💾 What number does this code show?
    let notes = ["Art", "Hindi", "Sports"];
    notes.push("Maths");
    show(notes.length);
19. 19.Which of these fits saving in the cloud? (a) a draft you are typing (b) a class leaderboard (c) your last game level (d) the sound on/off setting
20. 20.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 10 (d) 0
21. 21.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Zoya", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Arjun (c) Riya
22. 22.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
23. 23.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Art", "Science", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Music (c) Art (d) Science
24. 24.💾 What number does this code show?
    let stars = 8;
    stars = stars - 7;
    stars = stars + 1;
    show(stars);
25. 25.True or false: notes to read offline fits saving on the phone. (a) False (b) True
26. 26.💾 What number does this code show?
    let stars = 3;
    stars = stars - 1;
    stars = stars + 3;
    show(stars);
27. 27.True or false: your last game level fits saving in the cloud. (a) False (b) True
28. 28.💾 What number does this code show?
    let stars = 7;
    stars = stars - 1;
    stars = stars + 1;
    show(stars);
29. 29.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
30. 30.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Kites", "Sunrise"];
    show(songs[2]); (a) Kites (b) Stars (c) Sunrise
32. 32.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) notes to read offline (d) a shared to-do list
33. 33.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
34. 34.💾 What number does this code show?
    let notes = ["Music", "Hindi", "Art"];
    notes.push("Sports");
    show(notes.length);
35. 35.💾 What number does this code show?
    let lives = 4;
    lives = lives - 1;
    lives = lives + 2;
    show(lives);
36. 36.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) a shared chat (d) data saved on the phone
37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Hindi", "Science"];
    show(notes[0]); (a) Music (b) Science (c) Hindi
38. 38.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Science", "Maths", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Sports (c) Hindi (d) Maths
39. 39.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
40. 40.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) a draft you are typing (d) chat messages to friends

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