App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 730 · 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 is a variable? (a) a named box for a value (b) a phone setting (c) a type of screen (d) a picture
2. 2.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) on the phone (b) in the cloud
3. 3.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) chat messages to friends (d) your last game level
4. 4.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
5. 5.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a shared to-do list (d) your last game level
7. 7.💾 What number does this code show?
   let notes = ["Science", "Art"];
   notes.push("Hindi");
   show(notes.length);
8. 8.💾 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
9. 9.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Music", "Science"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Maths (b) Science (c) Music
10. 10.Which of these fits saving on the phone? (a) photos on two devices (b) notes to read offline (c) a class leaderboard (d) a shared to-do list
11. 11.Which of these fits saving on the phone? (a) the sound on/off setting (b) chat messages to friends (c) a shared to-do list (d) photos on two devices
12. 12.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Science", "Sports"];
    show(notes[0]); (a) Music (b) Sports (c) Science
13. 13.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) photos on two devices (d) a draft you are typing
14. 14.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
15. 15.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Kabir", "Aman", "Riya", "Arjun"];
    show(friends[1]); (a) Aman (b) Meera (c) Riya (d) Kabir
16. 16.💾 What number does this code show?
    let songs = ["Sunrise", "Stars"];
    songs.push("Rain");
    show(songs.length);
17. 17.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) a shared chat (d) data saved on the phone
18. 18.💾 What number does this code show?
    let points = 9;
    points = points - 5;
    points = points + 1;
    show(points);
19. 19.💾 What number does this code show?
    let songs = ["Monsoon", "Kites", "Sunrise"];
    songs.push("Ocean");
    songs.push("Rain");
    show(songs.length);
20. 20.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Art", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Sports (c) Maths (d) Hindi
21. 21.💾 What number does this code show?
    let notes = ["Maths", "Art", "Science", "Hindi"];
    notes.push("Sports");
    notes.push("Music");
    show(notes.length);
22. 22.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
23. 23.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a draft you are typing (d) chat messages to friends
24. 24.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
25. 25.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Meera", "Riya", "Aman", "Kabir"];
    show(friends[1]); (a) Zoya (b) Riya (c) Aman (d) Meera
26. 26.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
27. 27.💾 What number does this code show?
    let notes = ["Sports", "Art"];
    notes.push("Music");
    show(notes.length);
28. 28.💾 What number does this code show?
    let notes = ["Hindi", "Maths"];
    notes.push("Art");
    notes.push("Sports");
    show(notes.length);
29. 29.True or false: your last game level fits saving in the cloud. (a) False (b) True
30. 30.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Zoya", "Riya", "Aman", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Kabir (c) Aman (d) Riya
31. 31.💾 What number does this code show?
    let lives = 9;
    lives = lives - 8;
    lives = lives + 2;
    show(lives);
32. 32.💾 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
33. 33.Which of these fits saving in the cloud? (a) your last game level (b) a shared to-do list (c) the sound on/off setting (d) notes to read offline
34. 34.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Kabir", "Zoya", "Riya"];
    show(friends[3]); (a) Zoya (b) Meera (c) Riya (d) Kabir
35. 35.True or false: your last game level fits saving on the phone. (a) True (b) False
36. 36.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
37. 37.💾 What number does this code show?
    let notes = ["Science", "Sports", "Music", "Art"];
    notes.push("Hindi");
    notes.push("Maths");
    show(notes.length);
38. 38.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
39. 39.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Ocean", "Stars"];
    show(songs[0]); (a) Kites (b) Ocean (c) Stars
40. 40.💾 What number does this code show?
    let songs = ["Stars", "Kites", "Sunrise", "Monsoon"];
    songs.push("Rain");
    songs.push("Ocean");
    show(songs.length);

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