App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 210 · 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 notes = ["Maths", "Sports", "Art", "Music"];
   show(notes[3]); (a) Sports (b) Art (c) Maths (d) Music
2. 2.💾 What number does this code show?
   let friends = ["Zoya", "Kabir"];
   friends.push("Riya");
   friends.push("Aman");
   show(friends.length);
3. 3.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a class leaderboard (c) notes to read offline (d) a draft you are typing
4. 4.💾 Saving data in the cloud lets you ___. (a) never need a password (b) skip the internet (c) shrink the app (d) use it on any device
5. 5.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.💾 What does this code show? (Positions start at 0.)
   let notes = ["Sports", "Hindi", "Science", "Maths", "Art"];
   show(notes[4]); (a) Art (b) Hindi (c) Science (d) Sports
7. 7.True or false: your last game level fits saving on the phone. (a) False (b) True
8. 8.💾 What number does this code show?
   let score = 8;
   score = score - 6;
   score = score + 1;
   show(score);
9. 9.💾 What does this code show? (Positions start at 0.)
   let notes = ["Sports", "Maths", "Science"];
   show(notes[1]); (a) Sports (b) Science (c) Maths
10. 10.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Ocean", "Kites", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Stars (c) Rain (d) Ocean
11. 11.💾 What number does this code show?
    let points = 9;
    points = points - 4;
    points = points + 4;
    show(points);
12. 12.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Rain", "Monsoon", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Sunrise (c) Monsoon (d) Rain
13. 13.💾 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
14. 14.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
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.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Monsoon", "Rain", "Kites", "Ocean"];
    show(songs[2]); (a) Sunrise (b) Monsoon (c) Kites (d) Rain
17. 17.💾 What number does this code show?
    let notes = ["Art", "Music"];
    notes.push("Hindi");
    show(notes.length);
18. 18.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Hindi", "Music", "Sports", "Science"];
    show(notes[2]); (a) Hindi (b) Music (c) Sports (d) Maths
19. 19.💾 What number does this code show?
    let friends = ["Zoya", "Aman"];
    friends.push("Kabir");
    friends.push("Arjun");
    show(friends.length);
20. 20.True or false: photos on two devices fits saving on the phone. (a) False (b) True
21. 21.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a picture (d) a named box for a value
22. 22.💾 What number does this code show?
    let friends = ["Kabir", "Meera", "Riya", "Zoya"];
    friends.push("Aman");
    show(friends.length);
23. 23.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) the sound on/off setting (d) chat messages to friends
24. 24.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 4;
    show(score);
25. 25.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
26. 26.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
27. 27.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
28. 28.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) you send a message (c) the phone is lost (d) the screen turns off
29. 29.💾 What number does this code show?
    let stars = 5;
    stars = stars - 1;
    stars = stars + 5;
    show(stars);
30. 30.💾 Which can hold many values in order? (a) a single number (b) a button (c) a switch (d) a list
31. 31.💾 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
32. 32.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Science (c) Maths
33. 33.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Ocean", "Rain"];
    show(songs[1]); (a) Rain (b) Ocean (c) Sunrise
34. 34.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
35. 35.Which of these fits saving on the phone? (a) notes to read offline (b) chat messages to friends (c) a class leaderboard (d) a shared to-do list
36. 36.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
37. 37.Which of these fits saving in the cloud? (a) photos on two devices (b) the sound on/off setting (c) notes to read offline (d) a draft you are typing
38. 38.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Hindi", "Science"];
    show(notes[2]); (a) Hindi (b) Science (c) Music
39. 39.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
40. 40.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Kabir", "Riya", "Arjun", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Kabir (c) Aman (d) Riya

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