App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 556 · 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.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the app is closed (c) you send a message (d) the screen turns off
2. 2.💾 What number does this code show?
   let score = 7;
   score = score - 1;
   score = score + 3;
   show(score);
3. 3.💾 What is a variable? (a) a phone setting (b) a picture (c) a named box for a value (d) a type of screen
4. 4.💾 pop() takes off the last item. What does this code show?
   let notes = ["Sports", "Science", "Music", "Hindi", "Maths"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Science (b) Sports (c) Music (d) Hindi
5. 5.💾 pop() takes off the last item. What does this code show?
   let songs = ["Sunrise", "Monsoon", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Kites (b) Monsoon (c) Sunrise
6. 6.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
7. 7.💾 Which can hold many values in order? (a) a single number (b) a button (c) a switch (d) a list
8. 8.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) your last game level (d) a class leaderboard
10. 10.Which of these fits saving on the phone? (a) chat messages to friends (b) the sound on/off setting (c) a shared to-do list (d) a class leaderboard
11. 11.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
12. 12.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Riya", "Zoya", "Meera", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Zoya (d) Meera
13. 13.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
14. 14.💾 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
15. 15.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Maths", "Hindi", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Hindi (d) Science
16. 16.True or false: notes to read offline fits saving on the phone. (a) True (b) False
17. 17.💾 What number does this code show?
    let friends = ["Riya", "Aman"];
    friends.push("Kabir");
    show(friends.length);
18. 18.💾 What number does this code show?
    let lives = 6;
    lives = lives - 3;
    lives = lives + 5;
    show(lives);
19. 19.True or false: your last game level fits saving on the phone. (a) True (b) False
20. 20.💾 What number does this code show?
    let songs = ["Ocean", "Kites"];
    songs.push("Monsoon");
    show(songs.length);
21. 21.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Art", "Maths", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Music (c) Science (d) Art
22. 22.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Sports", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Science (c) Sports
23. 23.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 4;
    show(score);
24. 24.💾 What number does this code show?
    let notes = ["Hindi", "Art", "Music", "Maths"];
    notes.push("Science");
    show(notes.length);
25. 25.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
26. 26.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
27. 27.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
28. 28.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud backup (c) a shared chat (d) a cloud leaderboard
29. 29.💾 What number does this code show?
    let friends = ["Aman", "Riya"];
    friends.push("Arjun");
    friends.push("Kabir");
    show(friends.length);
30. 30.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
31. 31.💾 What number does this code show?
    let notes = ["Science", "Music"];
    notes.push("Maths");
    show(notes.length);
32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Kabir", "Riya", "Arjun", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Riya (c) Zoya (d) Arjun
33. 33.💾 What number does this code show?
    let songs = ["Ocean", "Stars"];
    songs.push("Kites");
    songs.push("Monsoon");
    show(songs.length);
34. 34.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
35. 35.💾 What number does this code show?
    let friends = ["Meera", "Aman", "Arjun"];
    friends.push("Riya");
    show(friends.length);
36. 36.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
37. 37.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 0 (d) 10
38. 38.Which of these fits saving in the cloud? (a) photos on two devices (b) your last game level (c) notes to read offline (d) a draft you are typing
39. 39.💾 What number does this code show?
    let notes = ["Hindi", "Maths", "Sports", "Science"];
    notes.push("Art");
    show(notes.length);
40. 40.💾 What number does this code show?
    let friends = ["Kabir", "Aman", "Arjun"];
    friends.push("Riya");
    show(friends.length);

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