App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 580 · 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 coins = 4;
   coins = coins - 2;
   coins = coins + 3;
   show(coins);
2. 2.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
3. 3.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) your last game level (d) a class leaderboard
4. 4.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
5. 5.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a picture (d) a type of screen
6. 6.💾 Which can hold many values in order? (a) a switch (b) a list (c) a button (d) a single number
7. 7.Which of these fits saving on the phone? (a) photos on two devices (b) the sound on/off setting (c) chat messages to friends (d) a class leaderboard
8. 8.💾 pop() takes off the last item. What does this code show?
   let friends = ["Zoya", "Arjun", "Kabir", "Aman"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Kabir (b) Arjun (c) Aman (d) Zoya
9. 9.💾 What does this code show? (Positions start at 0.)
   let songs = ["Monsoon", "Ocean", "Rain"];
   show(songs[0]); (a) Monsoon (b) Ocean (c) Rain
10. 10.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
11. 11.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
12. 12.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Kabir", "Aman", "Zoya", "Meera"];
    show(friends[2]); (a) Kabir (b) Riya (c) Aman (d) Zoya
13. 13.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Zoya", "Kabir", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Zoya (d) Kabir
14. 14.💾 What number does this code show?
    let coins = 5;
    coins = coins - 4;
    coins = coins + 4;
    show(coins);
15. 15.💾 What number does this code show?
    let friends = ["Riya", "Aman", "Zoya", "Arjun"];
    friends.push("Kabir");
    show(friends.length);
16. 16.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
17. 17.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Rain", "Sunrise"];
    show(songs[0]); (a) Rain (b) Sunrise (c) Kites
18. 18.Which of these fits saving on the phone? (a) a draft you are typing (b) photos on two devices (c) a class leaderboard (d) a shared to-do list
19. 19.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 10 (d) 0
20. 20.💾 What number does this code show?
    let points = 5;
    points = points - 2;
    points = points + 5;
    show(points);
21. 21.💾 What number does this code show?
    let songs = ["Rain", "Ocean", "Sunrise"];
    songs.push("Monsoon");
    show(songs.length);
22. 22.💾 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
23. 23.💾 Where should the app save your last game level: 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 = ["Rain", "Sunrise", "Kites"];
    show(songs[2]); (a) Rain (b) Sunrise (c) Kites
25. 25.💾 What number does this code show?
    let notes = ["Science", "Art"];
    notes.push("Music");
    show(notes.length);
26. 26.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
27. 27.💾 What number does this code show?
    let friends = ["Kabir", "Arjun", "Zoya", "Meera"];
    friends.push("Riya");
    friends.push("Aman");
    show(friends.length);
28. 28.💾 What number does this code show?
    let notes = ["Art", "Science"];
    notes.push("Hindi");
    notes.push("Music");
    show(notes.length);
29. 29.💾 What number does this code show?
    let songs = ["Kites", "Rain", "Stars", "Monsoon"];
    songs.push("Ocean");
    show(songs.length);
30. 30.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) your last game level (d) photos on two devices
31. 31.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
32. 32.💾 What number does this code show?
    let score = 7;
    score = score - 5;
    score = score + 1;
    show(score);
33. 33.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
34. 34.💾 What number does this code show?
    let stars = 8;
    stars = stars - 2;
    stars = stars + 1;
    show(stars);
35. 35.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Kabir", "Riya", "Meera"];
    show(friends[2]); (a) Riya (b) Kabir (c) Arjun (d) Meera
36. 36.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Aman", "Riya", "Meera", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Arjun (c) Aman (d) Riya
37. 37.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Sports", "Maths"];
    show(notes[0]); (a) Maths (b) Sports (c) Art
38. 38.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
39. 39.True or false: your last game level fits saving on the phone. (a) True (b) False
40. 40.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) notes to read offline (d) chat messages to friends

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