App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 807 · 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.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Riya", "Zoya", "Arjun"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Riya (b) Zoya (c) Arjun (d) Aman
2. 2.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a list (d) a button
3. 3.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) photos on two devices (d) notes to read offline
4. 4.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a picture (d) a named box for a value
5. 5.💾 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
6. 6.💾 What number does this code show?
   let songs = ["Sunrise", "Rain"];
   songs.push("Stars");
   show(songs.length);
7. 7.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud backup (c) a cloud leaderboard (d) a shared chat
8. 8.💾 pop() takes off the last item. What does this code show?
   let songs = ["Ocean", "Sunrise", "Rain"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Sunrise (b) Ocean (c) Rain
9. 9.💾 Saving data in the cloud lets you ___. (a) never need a password (b) skip the internet (c) shrink the app (d) use it on any device
10. 10.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Stars", "Kites", "Ocean", "Sunrise"];
    show(songs[3]); (a) Ocean (b) Kites (c) Stars (d) Monsoon
11. 11.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Maths", "Sports", "Art"];
    show(notes[0]); (a) Art (b) Maths (c) Science (d) Sports
12. 12.True or false: your last game level fits saving on the phone. (a) False (b) True
13. 13.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
14. 14.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Rain", "Sunrise", "Monsoon", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Monsoon (d) Rain
15. 15.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Arjun", "Aman", "Riya", "Kabir"];
    show(friends[1]); (a) Riya (b) Arjun (c) Meera (d) Aman
16. 16.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
17. 17.💾 What number does this code show?
    let score = 5;
    score = score - 3;
    score = score + 3;
    show(score);
18. 18.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a class leaderboard (d) the sound on/off setting
19. 19.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
20. 20.💾 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
21. 21.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
22. 22.💾 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
23. 23.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) notes to read offline (d) chat messages to friends
24. 24.💾 What number does this code show?
    let lives = 3;
    lives = lives - 1;
    lives = lives + 1;
    show(lives);
25. 25.💾 What number does this code show?
    let score = 4;
    score = score - 3;
    score = score + 5;
    show(score);
26. 26.💾 What number does this code show?
    let points = 3;
    points = points - 1;
    points = points + 3;
    show(points);
27. 27.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
28. 28.💾 What number does this code show?
    let songs = ["Sunrise", "Kites", "Rain"];
    songs.push("Ocean");
    show(songs.length);
29. 29.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
30. 30.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
31. 31.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Art", "Maths", "Music", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Maths (c) Music (d) Art
32. 32.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Sunrise", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Kites (c) Sunrise
33. 33.💾 What number does this code show?
    let notes = ["Science", "Sports", "Music"];
    notes.push("Art");
    show(notes.length);
34. 34.💾 What number does this code show?
    let lives = 7;
    lives = lives - 6;
    lives = lives + 1;
    show(lives);
35. 35.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 10 (d) 0
36. 36.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) a shared to-do list (d) a draft you are typing
37. 37.💾 What number does this code show?
    let notes = ["Art", "Hindi"];
    notes.push("Science");
    show(notes.length);
38. 38.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a shared to-do list (d) a draft you are typing
39. 39.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
40. 40.Which of these fits saving in the cloud? (a) your last game level (b) a class leaderboard (c) the sound on/off setting (d) a draft you are typing

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