App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 826 · 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 = 8;
   stars = stars - 7;
   stars = stars + 3;
   show(stars);
2. 2.💾 What does this code show? (Positions start at 0.)
   let notes = ["Maths", "Music", "Sports", "Hindi", "Art"];
   show(notes[2]); (a) Maths (b) Hindi (c) Music (d) Sports
3. 3.Which of these fits saving on the phone? (a) a draft you are typing (b) a class leaderboard (c) a shared to-do list (d) photos on two devices
4. 4.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
5. 5.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
6. 6.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 0 (d) 2
7. 7.💾 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
8. 8.💾 What does this code show? (Positions start at 0.)
   let notes = ["Science", "Hindi", "Maths"];
   show(notes[2]); (a) Maths (b) Hindi (c) Science
9. 9.💾 pop() takes off the last item. What does this code show?
   let friends = ["Aman", "Zoya", "Riya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Zoya (b) Riya (c) Aman
10. 10.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Kabir", "Arjun"];
    show(friends[0]); (a) Aman (b) Arjun (c) Kabir (d) Riya
11. 11.Which of these fits saving in the cloud? (a) a shared to-do list (b) your last game level (c) the sound on/off setting (d) notes to read offline
12. 12.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Zoya", "Riya", "Arjun", "Aman"];
    show(friends[3]); (a) Kabir (b) Arjun (c) Zoya (d) Riya
13. 13.Which of these fits saving in the cloud? (a) chat messages to friends (b) the sound on/off setting (c) notes to read offline (d) your last game level
14. 14.💾 What number does this code show?
    let score = 7;
    score = score - 2;
    score = score + 4;
    show(score);
15. 15.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
16. 16.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
17. 17.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) photos on two devices (d) the sound on/off setting
18. 18.💾 What number does this code show?
    let coins = 5;
    coins = coins - 2;
    coins = coins + 2;
    show(coins);
19. 19.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
20. 20.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Kites", "Monsoon", "Stars", "Ocean"];
    show(songs[3]); (a) Monsoon (b) Kites (c) Stars (d) Sunrise
21. 21.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the app is closed (d) the phone is lost
22. 22.💾 What number does this code show?
    let score = 5;
    score = score - 5;
    score = score + 5;
    show(score);
23. 23.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
24. 24.💾 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
25. 25.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
26. 26.💾 Which can hold many values in order? (a) a switch (b) a list (c) a button (d) a single number
27. 27.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Monsoon", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Monsoon
28. 28.Which of these fits saving on the phone? (a) chat messages to friends (b) a shared to-do list (c) notes to read offline (d) photos on two devices
29. 29.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Music", "Maths", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Music (c) Maths (d) Sports
30. 30.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
31. 31.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
32. 32.True or false: photos on two devices fits saving on the phone. (a) False (b) True
33. 33.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
34. 34.💾 What number does this code show?
    let friends = ["Arjun", "Meera", "Aman", "Riya"];
    friends.push("Kabir");
    show(friends.length);
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Stars", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Stars (c) Ocean
36. 36.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Arjun", "Riya", "Zoya", "Aman"];
    show(friends[2]); (a) Arjun (b) Zoya (c) Riya (d) Meera
37. 37.💾 What number does this code show?
    let points = 5;
    points = points - 4;
    points = points + 5;
    show(points);
38. 38.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
39. 39.💾 What number does this code show?
    let songs = ["Stars", "Rain"];
    songs.push("Ocean");
    songs.push("Kites");
    show(songs.length);
40. 40.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) chat messages to friends (d) your last game level

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