App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 497 · 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 picture (b) a type of screen (c) a named box for a value (d) a phone setting
2. 2.💾 What does this code show? (Positions start at 0.)
   let notes = ["Science", "Art", "Hindi"];
   show(notes[2]); (a) Art (b) Science (c) Hindi
3. 3.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
5. 5.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
6. 6.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Art", "Science", "Hindi"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Maths (d) Science
7. 7.💾 Which can hold many values in order? (a) a list (b) a button (c) a switch (d) a single number
8. 8.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the app is closed (c) the screen turns off (d) the phone is lost
9. 9.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) chat messages to friends (d) the sound on/off setting
10. 10.True or false: photos on two devices fits saving on the phone. (a) False (b) True
11. 11.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Maths", "Hindi", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Maths (c) Hindi (d) Science
12. 12.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
13. 13.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Monsoon", "Kites", "Stars", "Rain"];
    show(songs[1]); (a) Sunrise (b) Kites (c) Stars (d) Monsoon
14. 14.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 10 (c) 1 (d) 2
15. 15.💾 What number does this code show?
    let score = 6;
    score = score - 2;
    score = score + 3;
    show(score);
16. 16.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Rain", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Rain (c) Ocean (d) Monsoon
17. 17.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Art", "Science", "Hindi", "Maths"];
    show(notes[1]); (a) Art (b) Music (c) Science (d) Hindi
18. 18.💾 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
19. 19.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) use it on any device (d) skip the internet
20. 20.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
21. 21.💾 What number does this code show?
    let coins = 9;
    coins = coins - 4;
    coins = coins + 1;
    show(coins);
22. 22.True or false: your last game level fits saving on the phone. (a) True (b) False
23. 23.💾 What number does this code show?
    let notes = ["Science", "Hindi"];
    notes.push("Maths");
    show(notes.length);
24. 24.💾 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
25. 25.💾 What number does this code show?
    let points = 3;
    points = points - 2;
    points = points + 2;
    show(points);
26. 26.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) a class leaderboard (d) notes to read offline
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Ocean", "Stars"];
    show(songs[0]); (a) Stars (b) Monsoon (c) Ocean
28. 28.💾 What number does this code show?
    let notes = ["Maths", "Sports", "Music"];
    notes.push("Art");
    notes.push("Hindi");
    show(notes.length);
29. 29.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Monsoon
30. 30.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Rain", "Monsoon"];
    show(songs[1]); (a) Rain (b) Monsoon (c) Sunrise
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Stars", "Rain"];
    show(songs[0]); (a) Stars (b) Rain (c) Monsoon
32. 32.Which of these fits saving in the cloud? (a) a shared to-do list (b) a draft you are typing (c) your last game level (d) the sound on/off setting
33. 33.💾 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
34. 34.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Stars", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Rain (d) Stars
36. 36.💾 What number does this code show?
    let songs = ["Rain", "Ocean"];
    songs.push("Monsoon");
    show(songs.length);
37. 37.Which of these fits saving on the phone? (a) chat messages to friends (b) notes to read offline (c) a class leaderboard (d) photos on two devices
38. 38.Which of these fits saving on the phone? (a) a class leaderboard (b) a draft you are typing (c) chat messages to friends (d) photos on two devices
39. 39.💾 What number does this code show?
    let songs = ["Monsoon", "Sunrise", "Kites"];
    songs.push("Ocean");
    show(songs.length);
40. 40.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False

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