App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 420 · 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.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Maths", "Hindi", "Art"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Art (b) Hindi (c) Maths (d) Music
2. 2.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
3. 3.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
4. 4.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Sports", "Maths", "Art"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Art (b) Maths (c) Sports (d) Music
5. 5.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the screen turns off (c) the app is closed (d) you send a message
6. 6.💾 What does this code show? (Positions start at 0.)
   let friends = ["Aman", "Arjun", "Meera", "Kabir"];
   show(friends[1]); (a) Meera (b) Arjun (c) Aman (d) Kabir
7. 7.💾 What number does this code show?
   let lives = 5;
   lives = lives - 1;
   lives = lives + 5;
   show(lives);
8. 8.💾 What does this code show? (Positions start at 0.)
   let songs = ["Rain", "Stars", "Kites", "Ocean"];
   show(songs[3]); (a) Ocean (b) Rain (c) Stars (d) Kites
9. 9.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
10. 10.💾 What is a variable? (a) a picture (b) a named box for a value (c) a type of screen (d) a phone setting
11. 11.💾 Saving data in the cloud lets you ___. (a) never need a password (b) use it on any device (c) skip the internet (d) shrink the app
12. 12.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Monsoon", "Stars", "Rain", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Rain (d) Monsoon
13. 13.True or false: your last game level fits saving in the cloud. (a) True (b) False
14. 14.💾 What number does this code show?
    let stars = 6;
    stars = stars - 1;
    stars = stars + 2;
    show(stars);
15. 15.True or false: photos on two devices fits saving on the phone. (a) True (b) False
16. 16.💾 Which works with no internet at all? (a) a cloud backup (b) a shared chat (c) data saved on the phone (d) a cloud leaderboard
17. 17.💾 What number does this code show?
    let stars = 5;
    stars = stars - 5;
    stars = stars + 1;
    show(stars);
18. 18.💾 What number does this code show?
    let songs = ["Rain", "Kites"];
    songs.push("Monsoon");
    show(songs.length);
19. 19.💾 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
20. 20.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
21. 21.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
22. 22.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 1 (d) 2
23. 23.💾 What number does this code show?
    let notes = ["Hindi", "Maths"];
    notes.push("Sports");
    notes.push("Science");
    show(notes.length);
24. 24.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
25. 25.Which of these fits saving on the phone? (a) photos on two devices (b) the sound on/off setting (c) a shared to-do list (d) chat messages to friends
26. 26.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) photos on two devices
27. 27.💾 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
28. 28.💾 What number does this code show?
    let friends = ["Aman", "Arjun", "Meera", "Kabir"];
    friends.push("Riya");
    friends.push("Zoya");
    show(friends.length);
29. 29.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
30. 30.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
31. 31.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Stars", "Monsoon", "Rain", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Monsoon (d) Rain
32. 32.💾 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
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Hindi", "Art", "Science"];
    show(notes[0]); (a) Maths (b) Hindi (c) Art (d) Music
34. 34.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) your last game level (d) a shared to-do list
35. 35.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
36. 36.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Zoya", "Arjun", "Kabir"];
    show(friends[2]); (a) Meera (b) Kabir (c) Arjun (d) Zoya
37. 37.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Sunrise (c) Stars
38. 38.True or false: notes to read offline fits saving on the phone. (a) False (b) True
39. 39.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Stars", "Rain", "Sunrise"];
    show(songs[1]); (a) Sunrise (b) Stars (c) Rain (d) Ocean
40. 40.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) notes to read offline (d) chat messages to friends

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