App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 503 · 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.💾 pop() takes off the last item. What does this code show?
   let notes = ["Hindi", "Maths", "Art"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Hindi (b) Maths (c) Art
2. 2.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a picture (d) a named box for a value
3. 3.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
4. 4.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) use it on any device (d) skip the internet
5. 5.💾 What number does this code show?
   let score = 9;
   score = score - 5;
   score = score + 4;
   show(score);
6. 6.Which of these fits saving on the phone? (a) your last game level (b) photos on two devices (c) chat messages to friends (d) a class leaderboard
7. 7.💾 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
8. 8.Which of these fits saving on the phone? (a) a shared to-do list (b) a draft you are typing (c) chat messages to friends (d) a class leaderboard
9. 9.💾 What number does this code show?
   let stars = 3;
   stars = stars - 2;
   stars = stars + 1;
   show(stars);
10. 10.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Meera", "Riya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Meera (c) Kabir (d) Riya
11. 11.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) the sound on/off setting (d) chat messages to friends
12. 12.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) a draft you are typing (d) a class leaderboard
13. 13.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
14. 14.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
15. 15.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Stars", "Monsoon", "Rain", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Monsoon (c) Stars (d) Rain
16. 16.💾 What number does this code show?
    let score = 4;
    score = score - 3;
    score = score + 1;
    show(score);
17. 17.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
18. 18.Which of these fits saving on the phone? (a) the sound on/off setting (b) chat messages to friends (c) a class leaderboard (d) a shared to-do list
19. 19.💾 What number does this code show?
    let lives = 7;
    lives = lives - 6;
    lives = lives + 2;
    show(lives);
20. 20.💾 What number does this code show?
    let stars = 9;
    stars = stars - 5;
    stars = stars + 4;
    show(stars);
21. 21.💾 What number does this code show?
    let notes = ["Sports", "Music", "Hindi"];
    notes.push("Art");
    notes.push("Science");
    show(notes.length);
22. 22.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
23. 23.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) notes to read offline (d) photos on two devices
24. 24.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Meera", "Riya", "Kabir", "Aman"];
    show(friends[2]); (a) Kabir (b) Riya (c) Arjun (d) Meera
25. 25.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
26. 26.💾 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
27. 27.True or false: your last game level fits saving in the cloud. (a) True (b) False
28. 28.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
29. 29.💾 What number does this code show?
    let points = 7;
    points = points - 5;
    points = points + 3;
    show(points);
30. 30.💾 What number does this code show?
    let notes = ["Art", "Hindi", "Music", "Maths"];
    notes.push("Sports");
    notes.push("Science");
    show(notes.length);
31. 31.💾 What number does this code show?
    let notes = ["Hindi", "Sports"];
    notes.push("Art");
    show(notes.length);
32. 32.💾 What number does this code show?
    let songs = ["Rain", "Monsoon", "Stars"];
    songs.push("Ocean");
    show(songs.length);
33. 33.💾 What number does this code show?
    let friends = ["Meera", "Arjun", "Riya", "Zoya"];
    friends.push("Aman");
    show(friends.length);
34. 34.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
35. 35.💾 What number does this code show?
    let notes = ["Science", "Maths", "Sports", "Hindi"];
    notes.push("Art");
    notes.push("Music");
    show(notes.length);
36. 36.💾 What number does this code show?
    let notes = ["Music", "Maths"];
    notes.push("Art");
    notes.push("Hindi");
    show(notes.length);
37. 37.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Zoya", "Meera", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Meera (c) Zoya (d) Kabir
38. 38.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
39. 39.Which of these fits saving on the phone? (a) a class leaderboard (b) a shared to-do list (c) notes to read offline (d) photos on two devices
40. 40.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Sunrise", "Monsoon", "Ocean", "Stars"];
    show(songs[0]); (a) Ocean (b) Monsoon (c) Sunrise (d) Rain

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