App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 575 · 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 of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) the sound on/off setting (d) photos on two devices
2. 2.💾 What number does this code show?
   let notes = ["Science", "Hindi", "Art"];
   notes.push("Maths");
   notes.push("Sports");
   show(notes.length);
3. 3.💾 What number does this code show?
   let lives = 7;
   lives = lives - 2;
   lives = lives + 5;
   show(lives);
4. 4.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
5. 5.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
6. 6.💾 What number does this code show?
   let coins = 4;
   coins = coins - 1;
   coins = coins + 1;
   show(coins);
7. 7.💾 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
8. 8.💾 What number does this code show?
   let lives = 8;
   lives = lives - 3;
   lives = lives + 3;
   show(lives);
9. 9.💾 What number does this code show?
   let score = 8;
   score = score - 2;
   score = score + 2;
   show(score);
10. 10.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
11. 11.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
12. 12.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) the sound on/off setting (d) a class leaderboard
13. 13.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 10 (d) 1
14. 14.💾 What number does this code show?
    let stars = 6;
    stars = stars - 6;
    stars = stars + 5;
    show(stars);
15. 15.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
16. 16.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Science", "Maths", "Hindi"];
    show(notes[3]); (a) Science (b) Music (c) Art (d) Maths
17. 17.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Ocean", "Stars", "Monsoon"];
    show(songs[2]); (a) Kites (b) Ocean (c) Sunrise (d) Stars
18. 18.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Rain", "Sunrise", "Stars"];
    show(songs[2]); (a) Rain (b) Sunrise (c) Stars (d) Ocean
19. 19.True or false: notes to read offline fits saving on the phone. (a) True (b) False
20. 20.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
21. 21.💾 Which works with no internet at all? (a) a cloud leaderboard (b) data saved on the phone (c) a shared chat (d) a cloud backup
22. 22.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) skip the internet (c) never need a password (d) shrink the app
23. 23.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Hindi", "Sports", "Art"];
    show(notes[3]); (a) Sports (b) Music (c) Hindi (d) Maths
24. 24.True or false: your last game level fits saving on the phone. (a) False (b) True
25. 25.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
26. 26.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
27. 27.💾 What number does this code show?
    let songs = ["Stars", "Monsoon"];
    songs.push("Sunrise");
    show(songs.length);
28. 28.💾 What number does this code show?
    let score = 5;
    score = score - 2;
    score = score + 4;
    show(score);
29. 29.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) your last game level (d) a shared to-do list
30. 30.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Ocean", "Sunrise", "Kites", "Rain"];
    show(songs[0]); (a) Sunrise (b) Kites (c) Stars (d) Ocean
31. 31.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
32. 32.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 1;
    show(coins);
33. 33.💾 Which can hold many values in order? (a) a button (b) a list (c) a single number (d) a switch
34. 34.💾 What number does this code show?
    let points = 7;
    points = points - 2;
    points = points + 3;
    show(points);
35. 35.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Monsoon", "Sunrise", "Stars", "Kites"];
    show(songs[3]); (a) Stars (b) Monsoon (c) Rain (d) Sunrise
36. 36.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Science"];
    show(notes[1]); (a) Art (b) Hindi (c) Science
37. 37.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the screen turns off (c) the app is closed (d) the phone is lost
38. 38.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) your last game level (d) chat messages to friends
39. 39.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Maths (c) Hindi
40. 40.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Aman", "Kabir"];
    show(friends[2]); (a) Kabir (b) Riya (c) Aman

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