App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 783 · 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.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
2. 2.💾 pop() takes off the last item. What does this code show?
   let friends = ["Zoya", "Riya", "Arjun", "Kabir"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Riya (d) Arjun
3. 3.💾 What does this code show? (Positions start at 0.)
   let notes = ["Science", "Sports", "Maths"];
   show(notes[1]); (a) Maths (b) Sports (c) Science
4. 4.💾 What number does this code show?
   let notes = ["Sports", "Art"];
   notes.push("Maths");
   notes.push("Science");
   show(notes.length);
5. 5.💾 What number does this code show?
   let stars = 9;
   stars = stars - 2;
   stars = stars + 4;
   show(stars);
6. 6.💾 What does this code show? (Positions start at 0.)
   let friends = ["Zoya", "Arjun", "Meera", "Riya"];
   show(friends[0]); (a) Meera (b) Riya (c) Arjun (d) Zoya
7. 7.💾 pop() takes off the last item. What does this code show?
   let friends = ["Kabir", "Meera", "Aman", "Arjun"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Arjun (d) Kabir
8. 8.Which of these fits saving on the phone? (a) a shared to-do list (b) the sound on/off setting (c) photos on two devices (d) a class leaderboard
9. 9.Which of these fits saving on the phone? (a) chat messages to friends (b) a draft you are typing (c) photos on two devices (d) a class leaderboard
10. 10.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) the phone is lost (d) you send a message
11. 11.💾 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
12. 12.Which of these fits saving in the cloud? (a) your last game level (b) photos on two devices (c) notes to read offline (d) the sound on/off setting
13. 13.True or false: your last game level fits saving on the phone. (a) False (b) True
14. 14.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) chat messages to friends (d) a draft you are typing
15. 15.💾 Which can hold many values in order? (a) a single number (b) a list (c) a switch (d) a button
16. 16.💾 What number does this code show?
    let score = 8;
    score = score - 2;
    score = score + 3;
    show(score);
17. 17.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
18. 18.💾 What number does this code show?
    let points = 8;
    points = points - 8;
    points = points + 3;
    show(points);
19. 19.Which of these fits saving in the cloud? (a) your last game level (b) a shared to-do list (c) the sound on/off setting (d) notes to read offline
20. 20.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
21. 21.💾 What number does this code show?
    let points = 9;
    points = points - 5;
    points = points + 5;
    show(points);
22. 22.💾 What is a variable? (a) a picture (b) a phone setting (c) a type of screen (d) a named box for a value
23. 23.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Sports", "Music", "Maths", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Music (c) Sports (d) Maths
24. 24.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 1 (d) 10
25. 25.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Sunrise", "Monsoon", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Ocean (d) Monsoon
26. 26.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Stars", "Rain"];
    show(songs[2]); (a) Rain (b) Sunrise (c) Stars
27. 27.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
28. 28.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Music", "Art"];
    show(notes[0]); (a) Art (b) Maths (c) Music
29. 29.💾 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
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Rain", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Kites (d) Rain
31. 31.💾 What number does this code show?
    let points = 7;
    points = points - 5;
    points = points + 5;
    show(points);
32. 32.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Science", "Music"];
    show(notes[0]); (a) Science (b) Art (c) Music
33. 33.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
34. 34.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Rain", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Ocean (c) Stars
36. 36.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Monsoon", "Kites", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Monsoon (d) Kites
37. 37.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Zoya", "Meera"];
    show(friends[1]); (a) Zoya (b) Kabir (c) Meera
38. 38.True or false: notes to read offline fits saving on the phone. (a) True (b) False
39. 39.💾 What number does this code show?
    let notes = ["Hindi", "Maths"];
    notes.push("Art");
    show(notes.length);
40. 40.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone

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