App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 345 · 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) photos on two devices (c) a shared to-do list (d) a draft you are typing
2. 2.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
3. 3.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a class leaderboard (c) your last game level (d) notes to read offline
4. 4.💾 pop() takes off the last item. What does this code show?
   let notes = ["Hindi", "Maths", "Science"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Hindi (b) Science (c) Maths
5. 5.💾 What number does this code show?
   let stars = 4;
   stars = stars - 4;
   stars = stars + 4;
   show(stars);
6. 6.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
7. 7.💾 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
8. 8.💾 What does this code show? (Positions start at 0.)
   let notes = ["Art", "Hindi", "Music"];
   show(notes[0]); (a) Art (b) Music (c) Hindi
9. 9.Which of these fits saving on the phone? (a) chat messages to friends (b) a shared to-do list (c) your last game level (d) a class leaderboard
10. 10.💾 What number does this code show?
    let notes = ["Maths", "Music", "Art"];
    notes.push("Sports");
    show(notes.length);
11. 11.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
12. 12.💾 What number does this code show?
    let songs = ["Monsoon", "Ocean", "Rain", "Sunrise"];
    songs.push("Kites");
    songs.push("Stars");
    show(songs.length);
13. 13.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 0 (d) 2
14. 14.💾 What number does this code show?
    let friends = ["Meera", "Kabir", "Riya"];
    friends.push("Zoya");
    show(friends.length);
15. 15.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
16. 16.💾 What number does this code show?
    let songs = ["Stars", "Sunrise"];
    songs.push("Rain");
    show(songs.length);
17. 17.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Music", "Maths", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Art (c) Maths (d) Music
18. 18.💾 What is a variable? (a) a picture (b) a phone setting (c) a named box for a value (d) a type of screen
19. 19.💾 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
20. 20.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
21. 21.💾 What number does this code show?
    let stars = 7;
    stars = stars - 2;
    stars = stars + 4;
    show(stars);
22. 22.💾 What number does this code show?
    let coins = 9;
    coins = coins - 6;
    coins = coins + 3;
    show(coins);
23. 23.💾 Which can hold many values in order? (a) a button (b) a list (c) a switch (d) a single number
24. 24.💾 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
25. 25.True or false: your last game level fits saving on the phone. (a) True (b) False
26. 26.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
27. 27.💾 What number does this code show?
    let score = 6;
    score = score - 4;
    score = score + 2;
    show(score);
28. 28.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Riya", "Zoya", "Meera", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Meera (d) Riya
29. 29.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Ocean", "Monsoon", "Sunrise"];
    show(songs[2]); (a) Monsoon (b) Sunrise (c) Stars (d) Ocean
30. 30.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Maths", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Music
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Stars", "Ocean", "Sunrise", "Kites"];
    show(songs[4]); (a) Ocean (b) Stars (c) Kites (d) Rain
32. 32.💾 What number does this code show?
    let friends = ["Arjun", "Aman"];
    friends.push("Meera");
    show(friends.length);
33. 33.💾 What number does this code show?
    let notes = ["Maths", "Sports"];
    notes.push("Music");
    show(notes.length);
34. 34.💾 What number does this code show?
    let notes = ["Art", "Hindi"];
    notes.push("Science");
    notes.push("Music");
    show(notes.length);
35. 35.Which of these fits saving in the cloud? (a) chat messages to friends (b) notes to read offline (c) a draft you are typing (d) the sound on/off setting
36. 36.💾 What number does this code show?
    let notes = ["Hindi", "Science", "Music", "Art"];
    notes.push("Maths");
    show(notes.length);
37. 37.💾 What number does this code show?
    let friends = ["Aman", "Meera"];
    friends.push("Zoya");
    friends.push("Riya");
    show(friends.length);
38. 38.💾 What number does this code show?
    let songs = ["Rain", "Kites"];
    songs.push("Stars");
    songs.push("Sunrise");
    show(songs.length);
39. 39.💾 What number does this code show?
    let lives = 9;
    lives = lives - 8;
    lives = lives + 1;
    show(lives);
40. 40.True or false: notes to read offline fits saving on the phone. (a) True (b) False

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