App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 238 · 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 = 4;
   stars = stars - 3;
   stars = stars + 2;
   show(stars);
2. 2.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) chat messages to friends (d) a draft you are typing
3. 3.💾 What number does this code show?
   let notes = ["Hindi", "Art", "Music"];
   notes.push("Sports");
   notes.push("Maths");
   show(notes.length);
4. 4.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
5. 5.💾 What does this code show? (Positions start at 0.)
   let songs = ["Rain", "Sunrise", "Monsoon"];
   show(songs[0]); (a) Monsoon (b) Sunrise (c) Rain
6. 6.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
7. 7.💾 What number does this code show?
   let stars = 5;
   stars = stars - 4;
   stars = stars + 2;
   show(stars);
8. 8.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) chat messages to friends (d) notes to read offline
9. 9.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
10. 10.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Monsoon", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Monsoon (c) Stars
11. 11.💾 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
12. 12.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 10 (d) 0
13. 13.💾 What number does this code show?
    let notes = ["Science", "Maths", "Music"];
    notes.push("Art");
    notes.push("Hindi");
    show(notes.length);
14. 14.💾 Saving data in the cloud lets you ___. (a) never need a password (b) use it on any device (c) shrink the app (d) skip the internet
15. 15.💾 Which can hold many values in order? (a) a list (b) a switch (c) a single number (d) a button
16. 16.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Meera"];
    show(friends[2]); (a) Riya (b) Arjun (c) Meera
17. 17.💾 What number does this code show?
    let stars = 6;
    stars = stars - 1;
    stars = stars + 1;
    show(stars);
18. 18.True or false: photos on two devices fits saving on the phone. (a) True (b) False
19. 19.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Art", "Sports"];
    show(notes[0]); (a) Music (b) Sports (c) Art
20. 20.💾 What number does this code show?
    let notes = ["Art", "Sports", "Hindi", "Maths"];
    notes.push("Science");
    notes.push("Music");
    show(notes.length);
21. 21.💾 What number does this code show?
    let notes = ["Sports", "Music"];
    notes.push("Hindi");
    notes.push("Science");
    show(notes.length);
22. 22.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
23. 23.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
24. 24.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Ocean", "Monsoon", "Rain", "Sunrise"];
    show(songs[4]); (a) Kites (b) Monsoon (c) Sunrise (d) Ocean
25. 25.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Zoya", "Riya"];
    show(friends[0]); (a) Riya (b) Arjun (c) Zoya
26. 26.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
27. 27.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
28. 28.💾 What number does this code show?
    let notes = ["Art", "Maths", "Science"];
    notes.push("Music");
    show(notes.length);
29. 29.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Kabir", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Riya
30. 30.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Sports", "Maths", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Hindi (c) Art (d) Maths
31. 31.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Art", "Hindi", "Maths", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Science (d) Maths
32. 32.Which of these fits saving on the phone? (a) your last game level (b) a shared to-do list (c) chat messages to friends (d) photos on two devices
33. 33.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
34. 34.💾 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
35. 35.💾 What is a variable? (a) a type of screen (b) a picture (c) a phone setting (d) a named box for a value
36. 36.💾 What number does this code show?
    let friends = ["Riya", "Aman", "Zoya", "Kabir"];
    friends.push("Meera");
    show(friends.length);
37. 37.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Monsoon", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Monsoon (c) Kites
39. 39.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) a shared to-do list (d) notes to read offline
40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Sunrise", "Monsoon", "Ocean", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Sunrise (c) Monsoon (d) Ocean

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