App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 103 · 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) your last game level (c) a shared to-do list (d) chat messages to friends
2. 2.💾 pop() takes off the last item. What does this code show?
   let friends = ["Zoya", "Arjun", "Meera"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Zoya (b) Meera (c) Arjun
3. 3.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
4. 4.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Maths", "Science", "Art", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Maths (b) Art (c) Science (d) Music
5. 5.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.Which of these fits saving on the phone? (a) chat messages to friends (b) a draft you are typing (c) a class leaderboard (d) a shared to-do list
7. 7.💾 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
8. 8.💾 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
9. 9.True or false: photos on two devices fits saving on the phone. (a) True (b) False
10. 10.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Music", "Sports", "Science", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Music (c) Sports (d) Science
11. 11.💾 What is a variable? (a) a type of screen (b) a phone setting (c) a named box for a value (d) a picture
12. 12.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
13. 13.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
14. 14.💾 What number does this code show?
    let score = 3;
    score = score - 2;
    score = score + 3;
    show(score);
15. 15.💾 What number does this code show?
    let lives = 4;
    lives = lives - 4;
    lives = lives + 3;
    show(lives);
16. 16.💾 What number does this code show?
    let friends = ["Zoya", "Aman", "Meera", "Arjun"];
    friends.push("Riya");
    show(friends.length);
17. 17.True or false: your last game level fits saving on the phone. (a) True (b) False
18. 18.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
19. 19.💾 What number does this code show?
    let notes = ["Science", "Art", "Music"];
    notes.push("Sports");
    show(notes.length);
20. 20.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Sports", "Science", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Hindi (c) Sports (d) Music
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Zoya", "Meera"];
    show(friends[2]); (a) Zoya (b) Riya (c) Meera
22. 22.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the phone is lost (c) you send a message (d) the app is closed
23. 23.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
24. 24.Which of these fits saving in the cloud? (a) a class leaderboard (b) notes to read offline (c) your last game level (d) the sound on/off setting
25. 25.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
26. 26.💾 What number does this code show?
    let stars = 4;
    stars = stars - 2;
    stars = stars + 1;
    show(stars);
27. 27.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
28. 28.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) a shared to-do list (d) a draft you are typing
29. 29.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) chat messages to friends (d) your last game level
30. 30.💾 What number does this code show?
    let friends = ["Arjun", "Meera", "Kabir", "Riya"];
    friends.push("Aman");
    friends.push("Zoya");
    show(friends.length);
31. 31.💾 What number does this code show?
    let notes = ["Sports", "Art"];
    notes.push("Science");
    show(notes.length);
32. 32.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
33. 33.True or false: notes to read offline fits saving on the phone. (a) True (b) False
34. 34.💾 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
35. 35.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
36. 36.True or false: your last game level fits saving in the cloud. (a) False (b) True
37. 37.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Aman", "Riya"];
    show(friends[0]); (a) Aman (b) Arjun (c) Riya
38. 38.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 0 (d) 2
39. 39.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Science", "Hindi", "Sports", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Science (c) Sports (d) Hindi
40. 40.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone

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