App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 883 · 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 does this code show? (Positions start at 0.)
   let friends = ["Arjun", "Aman", "Kabir"];
   show(friends[2]); (a) Aman (b) Kabir (c) Arjun
2. 2.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) notes to read offline (d) a shared to-do list
3. 3.💾 pop() takes off the last item. What does this code show?
   let songs = ["Rain", "Stars", "Kites", "Monsoon", "Ocean"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Rain (b) Stars (c) Kites (d) Monsoon
4. 4.True or false: your last game level fits saving in the cloud. (a) False (b) True
5. 5.💾 What number does this code show?
   let songs = ["Ocean", "Kites"];
   songs.push("Monsoon");
   songs.push("Sunrise");
   show(songs.length);
6. 6.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.💾 Which can hold many values in order? (a) a single number (b) a list (c) a switch (d) a button
8. 8.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
9. 9.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
10. 10.Which of these fits saving in the cloud? (a) a draft you are typing (b) photos on two devices (c) the sound on/off setting (d) your last game level
11. 11.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
12. 12.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 1 (c) 10 (d) 2
13. 13.💾 What number does this code show?
    let songs = ["Sunrise", "Monsoon", "Rain"];
    songs.push("Kites");
    songs.push("Stars");
    show(songs.length);
14. 14.💾 What number does this code show?
    let notes = ["Sports", "Hindi"];
    notes.push("Maths");
    show(notes.length);
15. 15.True or false: notes to read offline fits saving on the phone. (a) True (b) False
16. 16.Which of these fits saving in the cloud? (a) a shared to-do list (b) your last game level (c) the sound on/off setting (d) notes to read offline
17. 17.💾 What number does this code show?
    let stars = 6;
    stars = stars - 1;
    stars = stars + 3;
    show(stars);
18. 18.💾 What number does this code show?
    let friends = ["Meera", "Kabir", "Riya", "Arjun"];
    friends.push("Zoya");
    show(friends.length);
19. 19.💾 What number does this code show?
    let notes = ["Music", "Art"];
    notes.push("Science");
    notes.push("Maths");
    show(notes.length);
20. 20.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a picture (d) a named box for a value
21. 21.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Aman", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Riya (c) Zoya
22. 22.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
23. 23.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) your last game level (d) chat messages to friends
24. 24.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
25. 25.💾 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
26. 26.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
27. 27.💾 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
28. 28.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Ocean", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Sunrise
29. 29.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
30. 30.True or false: photos on two devices fits saving on the phone. (a) False (b) True
31. 31.💾 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
32. 32.💾 What number does this code show?
    let friends = ["Zoya", "Kabir", "Riya", "Aman"];
    friends.push("Meera");
    friends.push("Arjun");
    show(friends.length);
33. 33.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Maths", "Music", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Music (d) Maths
34. 34.💾 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
35. 35.💾 What number does this code show?
    let stars = 7;
    stars = stars - 6;
    stars = stars + 4;
    show(stars);
36. 36.💾 What number does this code show?
    let notes = ["Music", "Art", "Science"];
    notes.push("Maths");
    show(notes.length);
37. 37.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Music", "Art", "Maths", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Hindi (c) Art (d) Music
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Rain", "Kites", "Monsoon", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Kites (c) Sunrise (d) Rain
39. 39.Which of these fits saving in the cloud? (a) a draft you are typing (b) a class leaderboard (c) the sound on/off setting (d) your last game level
40. 40.True or false: photos on two devices fits saving in the cloud. (a) True (b) False

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