App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 380 · 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 = ["Monsoon", "Stars"];
   songs.push("Rain");
   songs.push("Kites");
   show(songs.length);
2. 2.💾 Which can hold many values in order? (a) a list (b) a switch (c) a single number (d) a button
3. 3.💾 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
4. 4.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) chat messages to friends (d) the sound on/off setting
5. 5.💾 pop() takes off the last item. What does this code show?
   let songs = ["Stars", "Rain", "Ocean", "Monsoon"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Monsoon (b) Stars (c) Rain (d) Ocean
6. 6.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.💾 What does this code show? (Positions start at 0.)
   let notes = ["Music", "Maths", "Art"];
   show(notes[0]); (a) Art (b) Maths (c) Music
8. 8.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
9. 9.💾 What does this code show? (Positions start at 0.)
   let notes = ["Music", "Art", "Science", "Sports", "Hindi"];
   show(notes[0]); (a) Music (b) Art (c) Sports (d) Science
10. 10.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the app is closed (c) you send a message (d) the phone is lost
11. 11.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.💾 What is a variable? (a) a type of screen (b) a picture (c) a named box for a value (d) a phone setting
13. 13.💾 What number does this code show?
    let songs = ["Stars", "Rain"];
    songs.push("Kites");
    songs.push("Sunrise");
    show(songs.length);
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.💾 What number does this code show?
    let friends = ["Zoya", "Meera", "Arjun"];
    friends.push("Riya");
    show(friends.length);
16. 16.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Meera", "Zoya"];
    show(friends[0]); (a) Riya (b) Zoya (c) Aman (d) Meera
17. 17.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Stars", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Rain
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Zoya"];
    show(friends[0]); (a) Aman (b) Zoya (c) Riya
19. 19.True or false: your last game level fits saving in the cloud. (a) False (b) True
20. 20.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) a class leaderboard (d) the sound on/off setting
21. 21.Which of these fits saving on the phone? (a) a draft you are typing (b) a class leaderboard (c) a shared to-do list (d) photos on two devices
22. 22.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Zoya"];
    show(friends[2]); (a) Aman (b) Riya (c) Zoya
23. 23.💾 What number does this code show?
    let notes = ["Art", "Music"];
    notes.push("Sports");
    notes.push("Science");
    show(notes.length);
24. 24.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Music", "Science", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Sports (c) Music (d) Science
25. 25.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) skip the internet (c) shrink the app (d) never need a password
26. 26.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Arjun", "Zoya", "Meera"];
    show(friends[1]); (a) Zoya (b) Meera (c) Arjun (d) Aman
27. 27.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) notes to read offline (d) photos on two devices
28. 28.Which of these fits saving in the cloud? (a) a class leaderboard (b) notes to read offline (c) a draft you are typing (d) your last game level
29. 29.💾 What number does this code show?
    let score = 4;
    score = score - 3;
    score = score + 3;
    show(score);
30. 30.💾 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
31. 31.💾 What number does this code show?
    let friends = ["Zoya", "Aman", "Kabir"];
    friends.push("Riya");
    show(friends.length);
32. 32.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
33. 33.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
34. 34.True or false: photos on two devices fits saving on the phone. (a) True (b) False
35. 35.💾 What number does this code show?
    let stars = 6;
    stars = stars - 2;
    stars = stars + 3;
    show(stars);
36. 36.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Sunrise", "Kites", "Monsoon", "Ocean"];
    show(songs[0]); (a) Kites (b) Sunrise (c) Monsoon (d) Rain
37. 37.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
38. 38.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Meera", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Zoya (c) Meera
39. 39.💾 What number does this code show?
    let coins = 7;
    coins = coins - 1;
    coins = coins + 1;
    show(coins);
40. 40.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Art", "Hindi", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Hindi (c) Music (d) Sports

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