App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 923 · 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.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
2. 2.💾 What does this code show? (Positions start at 0.)
   let notes = ["Art", "Sports", "Hindi", "Maths", "Science"];
   show(notes[3]); (a) Art (b) Sports (c) Maths (d) Hindi
3. 3.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.💾 What number does this code show?
   let songs = ["Ocean", "Sunrise"];
   songs.push("Monsoon");
   songs.push("Rain");
   show(songs.length);
5. 5.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
6. 6.💾 What does this code show? (Positions start at 0.)
   let friends = ["Zoya", "Meera", "Aman", "Kabir"];
   show(friends[2]); (a) Zoya (b) Aman (c) Kabir (d) Meera
7. 7.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) use it on any device (c) never need a password (d) skip the internet
8. 8.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.💾 What does this code show? (Positions start at 0.)
   let songs = ["Kites", "Ocean", "Monsoon", "Stars", "Rain"];
   show(songs[2]); (a) Ocean (b) Monsoon (c) Stars (d) Kites
10. 10.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) notes to read offline (d) a class leaderboard
11. 11.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) on the phone (b) in the cloud
12. 12.Which of these fits saving in the cloud? (a) a class leaderboard (b) your last game level (c) notes to read offline (d) the sound on/off setting
13. 13.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Monsoon", "Kites", "Sunrise"];
    show(songs[3]); (a) Kites (b) Monsoon (c) Stars (d) Sunrise
14. 14.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Music", "Hindi", "Science"];
    show(notes[0]); (a) Hindi (b) Music (c) Maths (d) Art
15. 15.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Stars", "Monsoon", "Rain"];
    show(songs[0]); (a) Monsoon (b) Rain (c) Stars (d) Kites
16. 16.💾 What number does this code show?
    let friends = ["Meera", "Zoya", "Aman", "Riya"];
    friends.push("Kabir");
    show(friends.length);
17. 17.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a named box for a value (d) a picture
18. 18.💾 What number does this code show?
    let points = 9;
    points = points - 7;
    points = points + 2;
    show(points);
19. 19.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Riya", "Aman", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Riya (c) Kabir (d) Meera
20. 20.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Art", "Sports", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Science (c) Art (d) Sports
21. 21.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Science", "Hindi"];
    show(notes[0]); (a) Hindi (b) Music (c) Science
22. 22.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
23. 23.True or false: photos on two devices fits saving on the phone. (a) True (b) False
24. 24.True or false: your last game level fits saving in the cloud. (a) True (b) False
25. 25.💾 Which can hold many values in order? (a) a single number (b) a list (c) a switch (d) a button
26. 26.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Stars", "Rain", "Sunrise", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Rain (c) Stars (d) Sunrise
27. 27.Which of these fits saving in the cloud? (a) the sound on/off setting (b) chat messages to friends (c) notes to read offline (d) your last game level
28. 28.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
29. 29.💾 What number does this code show?
    let points = 3;
    points = points - 2;
    points = points + 1;
    show(points);
30. 30.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
31. 31.💾 What number does this code show?
    let coins = 3;
    coins = coins - 1;
    coins = coins + 4;
    show(coins);
32. 32.💾 What number does this code show?
    let friends = ["Zoya", "Aman", "Arjun"];
    friends.push("Riya");
    show(friends.length);
33. 33.💾 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
34. 34.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 0 (d) 2
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Stars", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Monsoon (c) Stars
36. 36.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Art", "Maths"];
    show(notes[2]); (a) Art (b) Sports (c) Maths
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Stars", "Rain", "Sunrise", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Sunrise (c) Rain (d) Stars
39. 39.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Rain", "Stars"];
    show(songs[1]); (a) Stars (b) Rain (c) Sunrise
40. 40.💾 What number does this code show?
    let stars = 3;
    stars = stars - 3;
    stars = stars + 5;
    show(stars);

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