App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 654 · 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 = 5;
   stars = stars - 2;
   stars = stars + 1;
   show(stars);
2. 2.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) chat messages to friends (d) the sound on/off setting
3. 3.💾 What number does this code show?
   let points = 7;
   points = points - 2;
   points = points + 5;
   show(points);
4. 4.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
5. 5.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
6. 6.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) skip the internet (c) never need a password (d) shrink the app
7. 7.💾 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
8. 8.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
9. 9.💾 What number does this code show?
   let notes = ["Maths", "Art", "Hindi"];
   notes.push("Science");
   show(notes.length);
10. 10.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Sports", "Science"];
    show(notes[0]); (a) Science (b) Sports (c) Hindi
11. 11.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 10 (d) 0
12. 12.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a draft you are typing (d) a class leaderboard
13. 13.💾 What is a variable? (a) a picture (b) a type of screen (c) a phone setting (d) a named box for a value
14. 14.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
15. 15.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Monsoon", "Sunrise", "Ocean", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Monsoon (c) Ocean (d) Sunrise
16. 16.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud backup (c) a shared chat (d) a cloud leaderboard
17. 17.💾 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
18. 18.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
19. 19.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) a shared to-do list (d) the sound on/off setting
20. 20.💾 What number does this code show?
    let stars = 4;
    stars = stars - 3;
    stars = stars + 5;
    show(stars);
21. 21.💾 What number does this code show?
    let points = 4;
    points = points - 2;
    points = points + 1;
    show(points);
22. 22.💾 What number does this code show?
    let friends = ["Riya", "Arjun", "Meera", "Zoya"];
    friends.push("Aman");
    show(friends.length);
23. 23.True or false: notes to read offline fits saving on the phone. (a) True (b) False
24. 24.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) your last game level (d) a shared to-do list
25. 25.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Stars", "Sunrise", "Rain"];
    show(songs[3]); (a) Ocean (b) Stars (c) Sunrise (d) Rain
26. 26.💾 What number does this code show?
    let points = 3;
    points = points - 3;
    points = points + 2;
    show(points);
27. 27.True or false: your last game level fits saving on the phone. (a) False (b) True
28. 28.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Sunrise", "Kites", "Monsoon", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Sunrise (c) Monsoon (d) Kites
29. 29.💾 What number does this code show?
    let points = 3;
    points = points - 1;
    points = points + 5;
    show(points);
30. 30.💾 What number does this code show?
    let coins = 5;
    coins = coins - 4;
    coins = coins + 5;
    show(coins);
31. 31.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) a class leaderboard (d) the sound on/off setting
32. 32.True or false: photos on two devices fits saving on the phone. (a) False (b) True
33. 33.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Kabir", "Meera", "Arjun", "Riya"];
    show(friends[0]); (a) Kabir (b) Meera (c) Arjun (d) Zoya
34. 34.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
35. 35.Which of these fits saving in the cloud? (a) a shared to-do list (b) your last game level (c) notes to read offline (d) the sound on/off setting
36. 36.💾 What number does this code show?
    let notes = ["Maths", "Science"];
    notes.push("Music");
    notes.push("Art");
    show(notes.length);
37. 37.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Hindi", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Music
38. 38.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Zoya", "Riya"];
    show(friends[2]); (a) Riya (b) Meera (c) Zoya
39. 39.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) in the cloud (b) on the phone
40. 40.True or false: a class leaderboard fits saving on the phone. (a) True (b) False

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