App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 332 · 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 = ["Science", "Art", "Music"];
   show(notes[0]); (a) Music (b) Art (c) Science
2. 2.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
3. 3.💾 What number does this code show?
   let lives = 9;
   lives = lives - 9;
   lives = lives + 1;
   show(lives);
4. 4.Which of these fits saving in the cloud? (a) chat messages to friends (b) the sound on/off setting (c) your last game level (d) a draft you are typing
5. 5.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) photos on two devices (d) your last game level
6. 6.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a class leaderboard (d) your last game level
7. 7.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) the sound on/off setting (d) a shared to-do list
8. 8.💾 pop() takes off the last item. What does this code show?
   let songs = ["Sunrise", "Rain", "Kites"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Rain (b) Sunrise (c) Kites
9. 9.True or false: notes to read offline fits saving on the phone. (a) False (b) True
10. 10.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
11. 11.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.💾 What number does this code show?
    let stars = 8;
    stars = stars - 2;
    stars = stars + 2;
    show(stars);
13. 13.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
14. 14.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Music", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Sports (c) Music
15. 15.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
16. 16.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
17. 17.💾 What number does this code show?
    let friends = ["Meera", "Riya"];
    friends.push("Aman");
    show(friends.length);
18. 18.💾 What number does this code show?
    let lives = 5;
    lives = lives - 5;
    lives = lives + 3;
    show(lives);
19. 19.💾 What number does this code show?
    let lives = 5;
    lives = lives - 1;
    lives = lives + 2;
    show(lives);
20. 20.💾 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
21. 21.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
22. 22.💾 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
23. 23.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
24. 24.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) chat messages to friends (d) notes to read offline
25. 25.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 2 (d) 0
26. 26.💾 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
27. 27.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Ocean", "Rain", "Stars", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Monsoon (c) Ocean (d) Stars
28. 28.💾 Which can hold many values in order? (a) a single number (b) a list (c) a switch (d) a button
29. 29.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Zoya", "Aman", "Riya"];
    show(friends[0]); (a) Riya (b) Arjun (c) Zoya (d) Aman
30. 30.💾 What number does this code show?
    let score = 7;
    score = score - 4;
    score = score + 1;
    show(score);
31. 31.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Arjun", "Zoya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Zoya (c) Arjun (d) Aman
32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Zoya", "Aman", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Riya (c) Zoya (d) Aman
33. 33.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) a shared to-do list (d) the sound on/off setting
34. 34.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Maths", "Music", "Hindi"];
    show(notes[3]); (a) Science (b) Music (c) Maths (d) Hindi
35. 35.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
36. 36.💾 What is a variable? (a) a picture (b) a named box for a value (c) a type of screen (d) a phone setting
37. 37.💾 What number does this code show?
    let notes = ["Music", "Sports"];
    notes.push("Art");
    show(notes.length);
38. 38.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Sports", "Maths", "Music", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Art (c) Music (d) Maths
39. 39.💾 What number does this code show?
    let friends = ["Meera", "Aman", "Riya", "Zoya"];
    friends.push("Arjun");
    show(friends.length);
40. 40.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True

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