App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 553 · 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 stars = 3;
   stars = stars - 1;
   stars = stars + 5;
   show(stars);
2. 2.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
3. 3.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
4. 4.💾 What does this code show? (Positions start at 0.)
   let friends = ["Arjun", "Meera", "Kabir"];
   show(friends[1]); (a) Kabir (b) Arjun (c) Meera
5. 5.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 shared to-do list
6. 6.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) photos on two devices (d) the sound on/off setting
8. 8.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Zoya", "Riya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Zoya (b) Aman (c) Riya
9. 9.💾 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
10. 10.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
11. 11.💾 What number does this code show?
    let notes = ["Art", "Music", "Maths", "Science"];
    notes.push("Sports");
    show(notes.length);
12. 12.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the app is closed (c) you send a message (d) the screen turns off
13. 13.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Arjun", "Meera"];
    show(friends[1]); (a) Meera (b) Aman (c) Arjun
14. 14.Which of these fits saving on the phone? (a) notes to read offline (b) a shared to-do list (c) a class leaderboard (d) photos on two devices
15. 15.Which of these fits saving on the phone? (a) a draft you are typing (b) photos on two devices (c) a shared to-do list (d) chat messages to friends
16. 16.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 1 (d) 10
17. 17.💾 What number does this code show?
    let songs = ["Sunrise", "Monsoon", "Ocean", "Kites"];
    songs.push("Rain");
    show(songs.length);
18. 18.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) notes to read offline (d) chat messages to friends
19. 19.💾 What number does this code show?
    let songs = ["Monsoon", "Stars", "Rain"];
    songs.push("Kites");
    show(songs.length);
20. 20.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Hindi", "Science"];
    show(notes[1]); (a) Hindi (b) Maths (c) Science (d) Art
21. 21.💾 What number does this code show?
    let lives = 3;
    lives = lives - 1;
    lives = lives + 3;
    show(lives);
22. 22.True or false: your last game level fits saving on the phone. (a) False (b) True
23. 23.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Art", "Music"];
    show(notes[0]); (a) Maths (b) Sports (c) Music (d) Art
24. 24.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Maths", "Sports"];
    show(notes[3]); (a) Maths (b) Art (c) Sports (d) Hindi
25. 25.💾 What number does this code show?
    let points = 7;
    points = points - 1;
    points = points + 4;
    show(points);
26. 26.True or false: your last game level fits saving in the cloud. (a) False (b) True
27. 27.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Hindi", "Art", "Sports", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Science (d) Sports
28. 28.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.💾 What is a variable? (a) a type of screen (b) a named box for a value (c) a picture (d) a phone setting
30. 30.💾 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
31. 31.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
32. 32.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Sports", "Maths", "Hindi"];
    show(notes[0]); (a) Music (b) Maths (c) Art (d) Sports
34. 34.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Ocean", "Sunrise", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Stars (d) Ocean
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Monsoon", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Monsoon (c) Sunrise
36. 36.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
37. 37.💾 What number does this code show?
    let friends = ["Aman", "Riya", "Zoya", "Meera"];
    friends.push("Arjun");
    friends.push("Kabir");
    show(friends.length);
38. 38.💾 What number does this code show?
    let score = 6;
    score = score - 6;
    score = score + 2;
    show(score);
39. 39.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Aman", "Meera", "Riya", "Zoya"];
    show(friends[4]); (a) Aman (b) Kabir (c) Meera (d) Zoya
40. 40.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Science", "Maths", "Sports", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Sports (c) Hindi (d) Maths

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