App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 666 · 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 type of screen (b) a phone setting (c) a named box for a value (d) a picture
2. 2.💾 pop() takes off the last item. What does this code show?
   let songs = ["Kites", "Stars", "Ocean"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Kites (b) Stars (c) Ocean
3. 3.Which of these fits saving on the phone? (a) the sound on/off setting (b) chat messages to friends (c) a shared to-do list (d) a class leaderboard
4. 4.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the screen turns off (c) the phone is lost (d) the app is closed
5. 5.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
6. 6.💾 What does this code show? (Positions start at 0.)
   let notes = ["Maths", "Music", "Hindi", "Science", "Art"];
   show(notes[2]); (a) Maths (b) Hindi (c) Science (d) Music
7. 7.Which of these fits saving on the phone? (a) chat messages to friends (b) a draft you are typing (c) a shared to-do list (d) photos on two devices
8. 8.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) your last game level (d) photos on two devices
9. 9.💾 What number does this code show?
   let songs = ["Sunrise", "Stars", "Monsoon", "Rain"];
   songs.push("Ocean");
   show(songs.length);
10. 10.💾 What number does this code show?
    let notes = ["Sports", "Hindi", "Science"];
    notes.push("Maths");
    show(notes.length);
11. 11.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) a shared to-do list (d) photos on two devices
12. 12.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Hindi", "Art"];
    show(notes[1]); (a) Hindi (b) Art (c) Sports
13. 13.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
14. 14.💾 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
15. 15.💾 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
16. 16.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) never need a password (d) shrink the app
17. 17.Which of these fits saving in the cloud? (a) chat messages to friends (b) a draft you are typing (c) your last game level (d) the sound on/off setting
18. 18.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 1 (d) 2
19. 19.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Kabir", "Aman", "Arjun", "Zoya"];
    show(friends[0]); (a) Kabir (b) Riya (c) Arjun (d) Aman
20. 20.💾 What number does this code show?
    let coins = 7;
    coins = coins - 2;
    coins = coins + 1;
    show(coins);
21. 21.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
22. 22.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a list (d) a button
23. 23.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
24. 24.True or false: your last game level fits saving in the cloud. (a) True (b) False
25. 25.Which of these fits saving in the cloud? (a) notes to read offline (b) photos on two devices (c) the sound on/off setting (d) a draft you are typing
26. 26.💾 What number does this code show?
    let notes = ["Hindi", "Maths", "Music", "Sports"];
    notes.push("Art");
    show(notes.length);
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Ocean", "Rain", "Monsoon", "Stars"];
    show(songs[4]); (a) Ocean (b) Rain (c) Sunrise (d) Stars
28. 28.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Science", "Sports"];
    show(notes[1]); (a) Hindi (b) Sports (c) Science
29. 29.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Ocean", "Monsoon", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Monsoon (d) Ocean
31. 31.Which of these fits saving in the cloud? (a) a class leaderboard (b) a draft you are typing (c) the sound on/off setting (d) your last game level
32. 32.True or false: photos on two devices fits saving on the phone. (a) True (b) False
33. 33.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Meera", "Riya", "Kabir", "Zoya"];
    show(friends[0]); (a) Kabir (b) Riya (c) Meera (d) Aman
34. 34.💾 What number does this code show?
    let stars = 4;
    stars = stars - 1;
    stars = stars + 4;
    show(stars);
35. 35.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
36. 36.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a shared chat (c) data saved on the phone (d) a cloud backup
37. 37.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Sports", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Music (c) Sports
38. 38.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
39. 39.💾 What number does this code show?
    let stars = 8;
    stars = stars - 6;
    stars = stars + 1;
    show(stars);
40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Monsoon", "Kites", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Kites (c) Monsoon (d) Stars

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