App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 780 · 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) notes to read offline (b) a shared to-do list (c) the sound on/off setting (d) your last game level
2. 2.💾 What does this code show? (Positions start at 0.)
   let friends = ["Zoya", "Kabir", "Meera", "Riya", "Arjun"];
   show(friends[3]); (a) Riya (b) Kabir (c) Zoya (d) Meera
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Sunrise", "Monsoon", "Stars"];
   show(songs[2]); (a) Ocean (b) Sunrise (c) Stars (d) Monsoon
4. 4.Which of these fits saving on the phone? (a) your last game level (b) a class leaderboard (c) photos on two devices (d) a shared to-do list
5. 5.Which of these fits saving in the cloud? (a) your last game level (b) a class leaderboard (c) notes to read offline (d) the sound on/off setting
6. 6.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) the phone is lost (d) you send a message
7. 7.💾 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
8. 8.💾 What number does this code show?
   let coins = 8;
   coins = coins - 2;
   coins = coins + 3;
   show(coins);
9. 9.💾 What does this code show? (Positions start at 0.)
   let friends = ["Riya", "Kabir", "Arjun"];
   show(friends[0]); (a) Kabir (b) Arjun (c) Riya
10. 10.💾 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
11. 11.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) use it on any device (d) skip the internet
12. 12.💾 What number does this code show?
    let friends = ["Kabir", "Aman"];
    friends.push("Meera");
    show(friends.length);
13. 13.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) chat messages to friends (d) the sound on/off setting
14. 14.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Art", "Music", "Science"];
    show(notes[0]); (a) Music (b) Science (c) Art (d) Hindi
15. 15.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
16. 16.💾 What number does this code show?
    let notes = ["Hindi", "Art"];
    notes.push("Maths");
    show(notes.length);
17. 17.💾 What number does this code show?
    let notes = ["Music", "Art", "Hindi"];
    notes.push("Sports");
    show(notes.length);
18. 18.💾 What number does this code show?
    let notes = ["Sports", "Science", "Music", "Art"];
    notes.push("Hindi");
    show(notes.length);
19. 19.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
20. 20.💾 Which works with no internet at all? (a) a shared chat (b) a cloud backup (c) a cloud leaderboard (d) data saved on the phone
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Aman", "Zoya"];
    show(friends[1]); (a) Zoya (b) Aman (c) Arjun
22. 22.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 2;
    show(coins);
23. 23.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) photos on two devices (d) the sound on/off setting
24. 24.💾 What number does this code show?
    let lives = 8;
    lives = lives - 5;
    lives = lives + 2;
    show(lives);
25. 25.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
26. 26.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Sports", "Science", "Maths"];
    show(notes[3]); (a) Science (b) Art (c) Sports (d) Maths
27. 27.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Science", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Music (c) Science
28. 28.💾 What is a variable? (a) a phone setting (b) a picture (c) a type of screen (d) a named box for a value
29. 29.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
30. 30.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
31. 31.💾 What number does this code show?
    let points = 9;
    points = points - 7;
    points = points + 5;
    show(points);
32. 32.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 10 (d) 2
33. 33.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
34. 34.True or false: photos on two devices fits saving on the phone. (a) False (b) True
35. 35.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Ocean", "Rain", "Stars", "Sunrise"];
    show(songs[4]); (a) Monsoon (b) Sunrise (c) Rain (d) Ocean
36. 36.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Kites", "Stars", "Sunrise"];
    show(songs[1]); (a) Kites (b) Rain (c) Sunrise (d) Stars
37. 37.True or false: your last game level fits saving on the phone. (a) True (b) False
38. 38.💾 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
39. 39.💾 What number does this code show?
    let notes = ["Science", "Art", "Maths", "Music"];
    notes.push("Sports");
    show(notes.length);
40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Sunrise", "Monsoon", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Monsoon (c) Sunrise (d) Kites

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