App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 297 · 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: your last game level fits saving on the phone. (a) False (b) True
2. 2.Which of these fits saving on the phone? (a) photos on two devices (b) the sound on/off setting (c) a shared to-do list (d) chat messages to friends
3. 3.💾 What number does this code show?
   let stars = 5;
   stars = stars - 1;
   stars = stars + 2;
   show(stars);
4. 4.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 10 (d) 0
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.💾 What number does this code show?
   let friends = ["Meera", "Kabir", "Zoya", "Aman"];
   friends.push("Riya");
   show(friends.length);
7. 7.💾 What number does this code show?
   let notes = ["Music", "Hindi"];
   notes.push("Art");
   show(notes.length);
8. 8.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
9. 9.💾 What number does this code show?
   let coins = 4;
   coins = coins - 4;
   coins = coins + 4;
   show(coins);
10. 10.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
11. 11.💾 What number does this code show?
    let coins = 8;
    coins = coins - 1;
    coins = coins + 4;
    show(coins);
12. 12.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
13. 13.💾 What number does this code show?
    let lives = 3;
    lives = lives - 3;
    lives = lives + 4;
    show(lives);
14. 14.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) shrink the app (d) never need a password
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Sports", "Science"];
    show(notes[2]); (a) Art (b) Maths (c) Sports (d) Science
16. 16.💾 What number does this code show?
    let score = 7;
    score = score - 6;
    score = score + 5;
    show(score);
17. 17.💾 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
18. 18.True or false: notes to read offline fits saving on the phone. (a) False (b) True
19. 19.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the screen turns off (d) the phone is lost
20. 20.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
21. 21.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
22. 22.💾 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
23. 23.True or false: photos on two devices fits saving on the phone. (a) False (b) True
24. 24.Which of these fits saving on the phone? (a) chat messages to friends (b) a draft you are typing (c) a class leaderboard (d) photos on two devices
25. 25.💾 What number does this code show?
    let friends = ["Meera", "Zoya", "Riya"];
    friends.push("Arjun");
    friends.push("Aman");
    show(friends.length);
26. 26.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Sports", "Hindi", "Art"];
    show(notes[0]); (a) Sports (b) Hindi (c) Art (d) Music
27. 27.💾 What number does this code show?
    let notes = ["Art", "Sports"];
    notes.push("Science");
    notes.push("Music");
    show(notes.length);
28. 28.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Monsoon", "Kites", "Ocean"];
    show(songs[2]); (a) Stars (b) Ocean (c) Monsoon (d) Kites
29. 29.💾 What number does this code show?
    let friends = ["Zoya", "Meera"];
    friends.push("Kabir");
    friends.push("Arjun");
    show(friends.length);
30. 30.💾 What number does this code show?
    let points = 9;
    points = points - 1;
    points = points + 1;
    show(points);
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Kites", "Rain"];
    show(songs[1]); (a) Sunrise (b) Rain (c) Kites
32. 32.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
33. 33.💾 What number does this code show?
    let notes = ["Music", "Science", "Maths", "Hindi"];
    notes.push("Art");
    show(notes.length);
34. 34.💾 What number does this code show?
    let notes = ["Sports", "Science"];
    notes.push("Music");
    notes.push("Art");
    show(notes.length);
35. 35.💾 Which can hold many values in order? (a) a switch (b) a list (c) a single number (d) a button
36. 36.💾 What number does this code show?
    let songs = ["Sunrise", "Monsoon", "Rain"];
    songs.push("Ocean");
    songs.push("Kites");
    show(songs.length);
37. 37.💾 What number does this code show?
    let notes = ["Music", "Art", "Maths"];
    notes.push("Science");
    notes.push("Sports");
    show(notes.length);
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Monsoon", "Kites", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Kites (d) Monsoon
39. 39.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
40. 40.💾 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

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