App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 363 · 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 number does this code show?
   let songs = ["Ocean", "Monsoon"];
   songs.push("Stars");
   show(songs.length);
2. 2.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) you send a message (d) the phone is lost
3. 3.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a picture (d) a type of screen
4. 4.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
5. 5.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a draft you are typing (d) chat messages to friends
6. 6.💾 What number does this code show?
   let notes = ["Music", "Art", "Sports"];
   notes.push("Hindi");
   show(notes.length);
7. 7.💾 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
8. 8.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
10. 10.💾 What number does this code show?
    let points = 8;
    points = points - 1;
    points = points + 5;
    show(points);
11. 11.💾 What number does this code show?
    let songs = ["Monsoon", "Rain", "Sunrise", "Stars"];
    songs.push("Kites");
    show(songs.length);
12. 12.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 0 (d) 1
13. 13.💾 Which can hold many values in order? (a) a single number (b) a button (c) a list (d) a switch
14. 14.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Sports", "Maths", "Music", "Hindi"];
    show(notes[3]); (a) Sports (b) Art (c) Maths (d) Music
15. 15.💾 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
16. 16.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) the sound on/off setting (d) a class leaderboard
17. 17.True or false: notes to read offline fits saving on the phone. (a) True (b) False
18. 18.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Zoya", "Arjun", "Meera", "Aman"];
    show(friends[4]); (a) Riya (b) Aman (c) Zoya (d) Arjun
19. 19.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
20. 20.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
21. 21.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Kites", "Sunrise", "Stars", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Sunrise (c) Kites (d) Stars
22. 22.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
23. 23.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) data saved on the phone (d) a shared chat
24. 24.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a shared to-do list (d) notes to read offline
25. 25.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Zoya", "Arjun", "Riya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Arjun (c) Zoya (d) Riya
26. 26.💾 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
27. 27.💾 What number does this code show?
    let notes = ["Maths", "Hindi"];
    notes.push("Music");
    show(notes.length);
28. 28.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.💾 What number does this code show?
    let coins = 8;
    coins = coins - 1;
    coins = coins + 5;
    show(coins);
30. 30.💾 What number does this code show?
    let notes = ["Music", "Science", "Sports", "Maths"];
    notes.push("Hindi");
    notes.push("Art");
    show(notes.length);
31. 31.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
32. 32.💾 What number does this code show?
    let points = 7;
    points = points - 7;
    points = points + 1;
    show(points);
33. 33.💾 What number does this code show?
    let notes = ["Art", "Science", "Hindi"];
    notes.push("Sports");
    notes.push("Maths");
    show(notes.length);
34. 34.💾 What number does this code show?
    let stars = 3;
    stars = stars - 1;
    stars = stars + 2;
    show(stars);
35. 35.True or false: your last game level fits saving on the phone. (a) False (b) True
36. 36.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
37. 37.💾 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
38. 38.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
39. 39.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Monsoon", "Stars", "Rain"];
    show(songs[3]); (a) Monsoon (b) Rain (c) Sunrise (d) Stars
40. 40.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Science", "Sports", "Maths"];
    show(notes[3]); (a) Art (b) Science (c) Maths (d) Sports

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