App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 355 · 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 works with no internet at all? (a) a cloud backup (b) data saved on the phone (c) a cloud leaderboard (d) a shared chat
2. 2.Which of these fits saving on the phone? (a) a draft you are typing (b) a shared to-do list (c) photos on two devices (d) a class leaderboard
3. 3.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) skip the internet (d) use it on any device
4. 4.💾 Which can hold many values in order? (a) a single number (b) a button (c) a switch (d) a list
5. 5.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.💾 What is a variable? (a) a type of screen (b) a picture (c) a named box for a value (d) a phone setting
7. 7.💾 What number does this code show?
   let score = 9;
   score = score - 1;
   score = score + 2;
   show(score);
8. 8.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a shared to-do list (d) your last game level
9. 9.💾 What does this code show? (Positions start at 0.)
   let songs = ["Kites", "Sunrise", "Rain", "Stars", "Monsoon"];
   show(songs[4]); (a) Rain (b) Kites (c) Monsoon (d) Sunrise
10. 10.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the phone is lost (c) the screen turns off (d) you send a message
11. 11.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 10 (d) 0
12. 12.💾 What number does this code show?
    let lives = 6;
    lives = lives - 2;
    lives = lives + 5;
    show(lives);
13. 13.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) the sound on/off setting (d) chat messages to friends
14. 14.💾 What number does this code show?
    let notes = ["Hindi", "Science"];
    notes.push("Music");
    notes.push("Maths");
    show(notes.length);
15. 15.Which of these fits saving in the cloud? (a) notes to read offline (b) a class leaderboard (c) the sound on/off setting (d) your last game level
16. 16.💾 What number does this code show?
    let notes = ["Art", "Science", "Hindi", "Sports"];
    notes.push("Music");
    show(notes.length);
17. 17.💾 What number does this code show?
    let songs = ["Kites", "Sunrise", "Monsoon", "Rain"];
    songs.push("Ocean");
    show(songs.length);
18. 18.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
19. 19.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
20. 20.True or false: photos on two devices fits saving on the phone. (a) True (b) False
21. 21.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Kabir", "Arjun", "Meera", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Kabir (c) Zoya (d) Meera
22. 22.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
23. 23.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
24. 24.💾 What number does this code show?
    let friends = ["Riya", "Kabir", "Meera"];
    friends.push("Zoya");
    friends.push("Arjun");
    show(friends.length);
25. 25.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Aman", "Meera", "Kabir", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Kabir (c) Zoya (d) Aman
26. 26.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Hindi", "Science"];
    show(notes[2]); (a) Science (b) Maths (c) Hindi
27. 27.Which of these fits saving in the cloud? (a) a draft you are typing (b) a shared to-do list (c) your last game level (d) notes to read offline
28. 28.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Ocean", "Sunrise", "Monsoon", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Monsoon (c) Sunrise (d) Rain
29. 29.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Zoya", "Meera"];
    show(friends[0]); (a) Zoya (b) Arjun (c) Meera
30. 30.💾 What number does this code show?
    let notes = ["Sports", "Maths", "Science", "Hindi"];
    notes.push("Art");
    show(notes.length);
31. 31.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
32. 32.💾 What number does this code show?
    let points = 7;
    points = points - 5;
    points = points + 2;
    show(points);
33. 33.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
34. 34.💾 What number does this code show?
    let notes = ["Art", "Music"];
    notes.push("Sports");
    notes.push("Hindi");
    show(notes.length);
35. 35.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
36. 36.True or false: notes to read offline fits saving on the phone. (a) False (b) True
37. 37.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
38. 38.💾 What number does this code show?
    let notes = ["Art", "Hindi"];
    notes.push("Maths");
    show(notes.length);
39. 39.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) chat messages to friends (d) notes to read offline
40. 40.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Ocean", "Monsoon", "Stars", "Sunrise"];
    show(songs[0]); (a) Rain (b) Ocean (c) Monsoon (d) Stars

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