App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 330 · 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.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
2. 2.💾 What number does this code show?
   let songs = ["Rain", "Monsoon", "Kites", "Ocean"];
   songs.push("Sunrise");
   songs.push("Stars");
   show(songs.length);
3. 3.Which of these fits saving in the cloud? (a) a shared to-do list (b) the sound on/off setting (c) notes to read offline (d) your last game level
4. 4.💾 pop() takes off the last item. What does this code show?
   let notes = ["Art", "Maths", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Art (b) Sports (c) Maths
5. 5.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
6. 6.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
7. 7.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
8. 8.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Arjun", "Meera", "Kabir", "Riya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Arjun (b) Kabir (c) Aman (d) Meera
9. 9.💾 pop() takes off the last item. What does this code show?
   let friends = ["Kabir", "Zoya", "Riya", "Meera"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Meera (d) Riya
10. 10.💾 What number does this code show?
    let notes = ["Music", "Science"];
    notes.push("Art");
    notes.push("Maths");
    show(notes.length);
11. 11.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) you send a message (c) the screen turns off (d) the app is closed
12. 12.True or false: photos on two devices fits saving on the phone. (a) True (b) False
13. 13.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a class leaderboard (d) a draft you are typing
14. 14.True or false: notes to read offline fits saving on the phone. (a) True (b) False
15. 15.💾 What number does this code show?
    let notes = ["Maths", "Art"];
    notes.push("Music");
    notes.push("Hindi");
    show(notes.length);
16. 16.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
17. 17.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) shrink the app (c) skip the internet (d) never need a password
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Zoya", "Kabir", "Meera", "Arjun"];
    show(friends[1]); (a) Meera (b) Zoya (c) Riya (d) Kabir
19. 19.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
20. 20.💾 What number does this code show?
    let songs = ["Rain", "Stars", "Monsoon", "Sunrise"];
    songs.push("Kites");
    show(songs.length);
21. 21.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
22. 22.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
23. 23.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
24. 24.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
25. 25.💾 Which can hold many values in order? (a) a single number (b) a switch (c) a button (d) a list
26. 26.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a type of screen (d) a picture
27. 27.💾 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
28. 28.Which of these fits saving in the cloud? (a) photos on two devices (b) a draft you are typing (c) your last game level (d) notes to read offline
29. 29.💾 What number does this code show?
    let songs = ["Stars", "Sunrise"];
    songs.push("Rain");
    show(songs.length);
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Science", "Sports"];
    show(notes[2]); (a) Science (b) Maths (c) Sports
31. 31.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 2 (c) 1 (d) 10
32. 32.Which of these fits saving in the cloud? (a) the sound on/off setting (b) chat messages to friends (c) a draft you are typing (d) notes to read offline
33. 33.💾 What number does this code show?
    let points = 7;
    points = points - 5;
    points = points + 2;
    show(points);
34. 34.💾 What number does this code show?
    let points = 5;
    points = points - 2;
    points = points + 1;
    show(points);
35. 35.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Music"];
    show(notes[0]); (a) Music (b) Hindi (c) Art
36. 36.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Hindi", "Maths", "Sports", "Art"];
    show(notes[3]); (a) Hindi (b) Science (c) Maths (d) Sports
38. 38.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Ocean", "Monsoon", "Kites"];
    show(songs[2]); (a) Kites (b) Sunrise (c) Monsoon (d) Ocean
39. 39.💾 What number does this code show?
    let friends = ["Arjun", "Aman"];
    friends.push("Riya");
    friends.push("Kabir");
    show(friends.length);
40. 40.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) your last game level (d) a class leaderboard

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