App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 40 · 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 = 8;
   stars = stars - 3;
   stars = stars + 3;
   show(stars);
2. 2.💾 What number does this code show?
   let score = 7;
   score = score - 5;
   score = score + 3;
   show(score);
3. 3.💾 pop() takes off the last item. What does this code show?
   let friends = ["Zoya", "Arjun", "Meera", "Aman"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Arjun (b) Aman (c) Zoya (d) Meera
4. 4.💾 What number does this code show?
   let songs = ["Monsoon", "Sunrise", "Kites", "Rain"];
   songs.push("Ocean");
   songs.push("Stars");
   show(songs.length);
5. 5.Which of these fits saving on the phone? (a) the sound on/off setting (b) a class leaderboard (c) photos on two devices (d) chat messages to friends
6. 6.💾 What is a variable? (a) a named box for a value (b) a type of screen (c) a phone setting (d) a picture
7. 7.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
8. 8.💾 What number does this code show?
   let friends = ["Aman", "Riya", "Kabir"];
   friends.push("Zoya");
   friends.push("Meera");
   show(friends.length);
9. 9.Which of these fits saving in the cloud? (a) your last game level (b) chat messages to friends (c) notes to read offline (d) the sound on/off setting
10. 10.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
11. 11.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Riya", "Zoya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Kabir (c) Riya (d) Zoya
12. 12.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) photos on two devices (d) the sound on/off setting
13. 13.True or false: your last game level fits saving in the cloud. (a) True (b) False
14. 14.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
15. 15.💾 What number does this code show?
    let friends = ["Aman", "Meera"];
    friends.push("Zoya");
    show(friends.length);
16. 16.💾 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
17. 17.💾 What number does this code show?
    let songs = ["Rain", "Kites", "Sunrise", "Stars"];
    songs.push("Ocean");
    songs.push("Monsoon");
    show(songs.length);
18. 18.💾 What number does this code show?
    let lives = 4;
    lives = lives - 3;
    lives = lives + 5;
    show(lives);
19. 19.💾 What number does this code show?
    let coins = 7;
    coins = coins - 3;
    coins = coins + 3;
    show(coins);
20. 20.💾 Which works with no internet at all? (a) a cloud backup (b) data saved on the phone (c) a shared chat (d) a cloud leaderboard
21. 21.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
22. 22.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Maths", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Maths (c) Music
23. 23.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
24. 24.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Sunrise", "Ocean", "Kites", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Kites (c) Sunrise (d) Monsoon
25. 25.💾 What number does this code show?
    let notes = ["Hindi", "Music"];
    notes.push("Sports");
    show(notes.length);
26. 26.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a class leaderboard (c) notes to read offline (d) a draft you are typing
27. 27.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Arjun", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Meera (c) Arjun
28. 28.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
29. 29.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Hindi", "Science", "Sports", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Science (c) Hindi (d) Sports
30. 30.Which of these fits saving in the cloud? (a) notes to read offline (b) a shared to-do list (c) a draft you are typing (d) your last game level
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Sunrise", "Stars"];
    show(songs[1]); (a) Ocean (b) Stars (c) Sunrise
32. 32.True or false: notes to read offline fits saving on the phone. (a) False (b) True
33. 33.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
34. 34.💾 What number does this code show?
    let points = 4;
    points = points - 2;
    points = points + 2;
    show(points);
35. 35.Which of these fits saving on the phone? (a) a draft you are typing (b) a class leaderboard (c) a shared to-do list (d) chat messages to friends
36. 36.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
37. 37.💾 What number does this code show?
    let friends = ["Aman", "Kabir", "Zoya"];
    friends.push("Riya");
    show(friends.length);
38. 38.💾 Which can hold many values in order? (a) a single number (b) a button (c) a switch (d) a list
39. 39.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
40. 40.💾 Saving data in the cloud lets you ___. (a) never need a password (b) skip the internet (c) use it on any device (d) shrink the app

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