App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 508 · 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 = ["Maths", "Hindi", "Art"];
   notes.push("Science");
   notes.push("Music");
   show(notes.length);
2. 2.💾 Which can hold many values in order? (a) a single number (b) a switch (c) a button (d) a list
3. 3.True or false: photos on two devices fits saving on the phone. (a) True (b) False
4. 4.💾 What is a variable? (a) a picture (b) a named box for a value (c) a type of screen (d) a phone setting
5. 5.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) the sound on/off setting (d) a shared to-do list
6. 6.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.💾 What number does this code show?
   let friends = ["Arjun", "Riya", "Aman", "Zoya"];
   friends.push("Kabir");
   friends.push("Meera");
   show(friends.length);
8. 8.💾 What does this code show? (Positions start at 0.)
   let songs = ["Kites", "Stars", "Sunrise"];
   show(songs[2]); (a) Stars (b) Sunrise (c) Kites
9. 9.💾 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
10. 10.💾 What number does this code show?
    let notes = ["Art", "Science"];
    notes.push("Sports");
    notes.push("Music");
    show(notes.length);
11. 11.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Ocean", "Rain"];
    show(songs[0]); (a) Rain (b) Sunrise (c) Ocean
12. 12.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
13. 13.💾 What number does this code show?
    let score = 4;
    score = score - 1;
    score = score + 4;
    show(score);
14. 14.💾 What number does this code show?
    let friends = ["Kabir", "Riya"];
    friends.push("Meera");
    show(friends.length);
15. 15.💾 What number does this code show?
    let coins = 6;
    coins = coins - 1;
    coins = coins + 2;
    show(coins);
16. 16.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
17. 17.💾 What number does this code show?
    let songs = ["Ocean", "Stars"];
    songs.push("Sunrise");
    songs.push("Kites");
    show(songs.length);
18. 18.True or false: notes to read offline fits saving on the phone. (a) False (b) True
19. 19.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) chat messages to friends (d) notes to read offline
20. 20.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) photos on two devices (d) a draft you are typing
21. 21.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Monsoon", "Ocean"];
    show(songs[0]); (a) Sunrise (b) Ocean (c) Monsoon
22. 22.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Aman", "Kabir", "Meera", "Zoya"];
    show(friends[2]); (a) Meera (b) Kabir (c) Aman (d) Riya
23. 23.💾 What number does this code show?
    let stars = 3;
    stars = stars - 2;
    stars = stars + 3;
    show(stars);
24. 24.💾 What number does this code show?
    let notes = ["Art", "Science", "Music", "Hindi"];
    notes.push("Maths");
    show(notes.length);
25. 25.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) never need a password (c) shrink the app (d) use it on any device
26. 26.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
27. 27.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
28. 28.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) your last game level (d) a shared to-do list
29. 29.💾 What number does this code show?
    let notes = ["Music", "Science"];
    notes.push("Hindi");
    notes.push("Sports");
    show(notes.length);
30. 30.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
31. 31.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Stars", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Rain (c) Monsoon
32. 32.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 2 (c) 10 (d) 1
33. 33.Which of these fits saving on the phone? (a) a class leaderboard (b) notes to read offline (c) chat messages to friends (d) a shared to-do list
34. 34.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Art", "Hindi"];
    show(notes[2]); (a) Hindi (b) Art (c) Sports
35. 35.💾 What number does this code show?
    let friends = ["Riya", "Meera", "Zoya", "Kabir"];
    friends.push("Aman");
    friends.push("Arjun");
    show(friends.length);
36. 36.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) on the phone (b) in the cloud
37. 37.💾 What number does this code show?
    let songs = ["Sunrise", "Rain", "Monsoon"];
    songs.push("Kites");
    songs.push("Ocean");
    show(songs.length);
38. 38.💾 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
39. 39.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
40. 40.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a shared chat (c) data saved on the phone (d) a cloud backup

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