App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 530 · 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.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
2. 2.💾 What does this code show? (Positions start at 0.)
   let friends = ["Kabir", "Arjun", "Meera"];
   show(friends[2]); (a) Arjun (b) Kabir (c) Meera
3. 3.💾 What does this code show? (Positions start at 0.)
   let notes = ["Science", "Art", "Music", "Hindi"];
   show(notes[1]); (a) Science (b) Art (c) Music (d) Hindi
4. 4.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
5. 5.💾 pop() takes off the last item. What does this code show?
   let notes = ["Hindi", "Art", "Sports", "Music", "Maths"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Music (c) Art (d) Hindi
6. 6.💾 What number does this code show?
   let notes = ["Art", "Maths"];
   notes.push("Music");
   show(notes.length);
7. 7.💾 What number does this code show?
   let notes = ["Science", "Sports"];
   notes.push("Hindi");
   show(notes.length);
8. 8.💾 What is a variable? (a) a named box for a value (b) a picture (c) a phone setting (d) a type of screen
9. 9.💾 What does this code show? (Positions start at 0.)
   let songs = ["Rain", "Stars", "Kites", "Ocean", "Monsoon"];
   show(songs[0]); (a) Kites (b) Stars (c) Rain (d) Ocean
10. 10.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Arjun", "Riya", "Aman"];
    show(friends[2]); (a) Kabir (b) Arjun (c) Meera (d) Riya
11. 11.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Meera", "Aman", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Riya (c) Meera (d) Aman
12. 12.💾 Which can hold many values in order? (a) a list (b) a single number (c) a switch (d) a button
13. 13.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) your last game level (d) a class leaderboard
14. 14.💾 What number does this code show?
    let coins = 7;
    coins = coins - 5;
    coins = coins + 1;
    show(coins);
15. 15.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
16. 16.💾 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
17. 17.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the screen turns off (c) the app is closed (d) you send a message
18. 18.True or false: photos on two devices fits saving on the phone. (a) False (b) True
19. 19.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) chat messages to friends (d) a draft you are typing
20. 20.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
21. 21.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
22. 22.💾 What number does this code show?
    let score = 4;
    score = score - 3;
    score = score + 2;
    show(score);
23. 23.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Kites", "Sunrise", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Ocean (c) Kites (d) Sunrise
24. 24.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
25. 25.💾 What number does this code show?
    let songs = ["Sunrise", "Monsoon", "Kites"];
    songs.push("Ocean");
    show(songs.length);
26. 26.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Arjun", "Zoya", "Meera", "Kabir"];
    show(friends[3]); (a) Meera (b) Zoya (c) Riya (d) Arjun
27. 27.Which of these fits saving in the cloud? (a) the sound on/off setting (b) photos on two devices (c) a draft you are typing (d) your last game level
28. 28.💾 What number does this code show?
    let notes = ["Maths", "Hindi"];
    notes.push("Music");
    show(notes.length);
29. 29.💾 What number does this code show?
    let stars = 5;
    stars = stars - 5;
    stars = stars + 1;
    show(stars);
30. 30.Which of these fits saving on the phone? (a) photos on two devices (b) your last game level (c) a class leaderboard (d) chat messages to friends
31. 31.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
32. 32.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
33. 33.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
34. 34.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 10 (c) 2 (d) 1
35. 35.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) a shared to-do list (d) your last game level
36. 36.💾 What number does this code show?
    let score = 6;
    score = score - 1;
    score = score + 5;
    show(score);
37. 37.💾 What number does this code show?
    let friends = ["Arjun", "Riya"];
    friends.push("Aman");
    show(friends.length);
38. 38.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Kites", "Stars", "Monsoon", "Sunrise"];
    show(songs[0]); (a) Kites (b) Monsoon (c) Ocean (d) Stars
39. 39.💾 What number does this code show?
    let lives = 3;
    lives = lives - 2;
    lives = lives + 5;
    show(lives);
40. 40.💾 What number does this code show?
    let coins = 6;
    coins = coins - 4;
    coins = coins + 5;
    show(coins);

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