App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 197 · 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 notes = ["Art", "Music"];
   notes.push("Maths");
   show(notes.length);
2. 2.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) notes to read offline (d) a shared to-do list
3. 3.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
4. 4.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
5. 5.💾 What is a variable? (a) a type of screen (b) a picture (c) a named box for a value (d) a phone setting
6. 6.💾 What number does this code show?
   let points = 6;
   points = points - 6;
   points = points + 4;
   show(points);
7. 7.💾 What does this code show? (Positions start at 0.)
   let notes = ["Music", "Science", "Art"];
   show(notes[1]); (a) Art (b) Music (c) Science
8. 8.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
9. 9.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) a draft you are typing (d) a class leaderboard
10. 10.True or false: notes to read offline fits saving on the phone. (a) False (b) True
11. 11.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) a shared to-do list (d) notes to read offline
12. 12.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
13. 13.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
14. 14.True or false: your last game level fits saving in the cloud. (a) True (b) False
15. 15.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 2 (c) 10 (d) 1
16. 16.💾 What number does this code show?
    let songs = ["Monsoon", "Stars"];
    songs.push("Kites");
    show(songs.length);
17. 17.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
18. 18.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Hindi", "Music"];
    show(notes[0]); (a) Art (b) Maths (c) Music (d) Hindi
19. 19.True or false: photos on two devices fits saving on the phone. (a) True (b) False
20. 20.💾 What number does this code show?
    let songs = ["Stars", "Monsoon", "Ocean", "Sunrise"];
    songs.push("Rain");
    show(songs.length);
21. 21.💾 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
22. 22.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Riya", "Kabir", "Arjun"];
    show(friends[0]); (a) Riya (b) Arjun (c) Kabir (d) Zoya
23. 23.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 5;
    show(coins);
24. 24.💾 What number does this code show?
    let friends = ["Kabir", "Riya", "Arjun"];
    friends.push("Aman");
    friends.push("Zoya");
    show(friends.length);
25. 25.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
26. 26.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Meera", "Kabir", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Kabir (c) Riya (d) Meera
27. 27.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the phone is lost (c) you send a message (d) the app is closed
28. 28.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud leaderboard (c) a shared chat (d) a cloud backup
29. 29.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Music", "Art", "Maths"];
    show(notes[1]); (a) Hindi (b) Art (c) Maths (d) Music
31. 31.💾 What number does this code show?
    let lives = 7;
    lives = lives - 2;
    lives = lives + 5;
    show(lives);
32. 32.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
33. 33.💾 What number does this code show?
    let stars = 5;
    stars = stars - 3;
    stars = stars + 2;
    show(stars);
34. 34.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) never need a password (c) skip the internet (d) shrink the app
35. 35.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Zoya", "Aman", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Meera (c) Riya (d) Zoya
36. 36.💾 What number does this code show?
    let score = 7;
    score = score - 2;
    score = score + 5;
    show(score);
37. 37.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Aman", "Arjun", "Zoya", "Riya"];
    show(friends[4]); (a) Riya (b) Meera (c) Aman (d) Arjun
38. 38.💾 What number does this code show?
    let notes = ["Maths", "Hindi", "Science"];
    notes.push("Art");
    notes.push("Music");
    show(notes.length);
39. 39.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Sunrise (c) Stars

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