App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 999 · 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.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud backup (c) a cloud leaderboard (d) a shared chat
2. 2.💾 pop() takes off the last item. What does this code show?
   let songs = ["Rain", "Monsoon", "Sunrise", "Ocean"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Rain (b) Sunrise (c) Monsoon (d) Ocean
3. 3.💾 Which can hold many values in order? (a) a switch (b) a button (c) a single number (d) a list
4. 4.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) the sound on/off setting (d) photos on two devices
5. 5.💾 What does this code show? (Positions start at 0.)
   let songs = ["Monsoon", "Ocean", "Rain", "Stars"];
   show(songs[3]); (a) Stars (b) Rain (c) Monsoon (d) Ocean
6. 6.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.Which of these fits saving in the cloud? (a) a class leaderboard (b) notes to read offline (c) the sound on/off setting (d) a draft you are typing
8. 8.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) skip the internet (d) use it on any device
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) Riya (b) Zoya (c) Aman
10. 10.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) a draft you are typing (d) chat messages to friends
11. 11.True or false: notes to read offline fits saving on the phone. (a) True (b) False
12. 12.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the phone is lost (c) you send a message (d) the screen turns off
13. 13.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
14. 14.💾 What is a variable? (a) a named box for a value (b) a type of screen (c) a phone setting (d) a picture
15. 15.True or false: your last game level fits saving on the phone. (a) True (b) False
16. 16.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Music", "Sports", "Science", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Science (c) Sports (d) Maths
17. 17.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Kites", "Ocean", "Sunrise", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Ocean (c) Sunrise (d) Kites
18. 18.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
19. 19.💾 What number does this code show?
    let lives = 5;
    lives = lives - 4;
    lives = lives + 2;
    show(lives);
20. 20.💾 What number does this code show?
    let lives = 7;
    lives = lives - 3;
    lives = lives + 5;
    show(lives);
21. 21.💾 What number does this code show?
    let coins = 4;
    coins = coins - 2;
    coins = coins + 2;
    show(coins);
22. 22.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Meera", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Meera (c) Zoya
23. 23.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
24. 24.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
25. 25.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Sunrise", "Ocean", "Kites", "Stars"];
    show(songs[2]); (a) Kites (b) Sunrise (c) Ocean (d) Rain
26. 26.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Kabir", "Meera", "Aman", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Meera (c) Kabir (d) Aman
27. 27.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) a class leaderboard (d) the sound on/off setting
28. 28.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Music", "Sports", "Art", "Hindi"];
    show(notes[1]); (a) Science (b) Sports (c) Art (d) Music
29. 29.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
30. 30.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Meera", "Zoya", "Arjun", "Riya"];
    show(friends[0]); (a) Zoya (b) Kabir (c) Arjun (d) Meera
31. 31.Which of these fits saving on the phone? (a) photos on two devices (b) a draft you are typing (c) chat messages to friends (d) a class leaderboard
32. 32.Which of these fits saving on the phone? (a) chat messages to friends (b) your last game level (c) a class leaderboard (d) photos on two devices
33. 33.💾 What number does this code show?
    let friends = ["Kabir", "Riya"];
    friends.push("Aman");
    show(friends.length);
34. 34.💾 What number does this code show?
    let songs = ["Kites", "Stars", "Monsoon", "Ocean"];
    songs.push("Rain");
    show(songs.length);
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Monsoon", "Stars", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Monsoon (c) Kites (d) Stars
36. 36.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 0 (d) 10
37. 37.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Arjun", "Kabir"];
    show(friends[1]); (a) Aman (b) Kabir (c) Arjun
38. 38.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Science"];
    show(notes[2]); (a) Science (b) Art (c) Hindi
39. 39.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Meera"];
    show(friends[1]); (a) Meera (b) Riya (c) Aman
40. 40.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Maths", "Music", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Hindi (d) Music

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