App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 809 · 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 can hold many values in order? (a) a list (b) a single number (c) a switch (d) a button
2. 2.💾 pop() takes off the last item. What does this code show?
   let notes = ["Art", "Science", "Hindi", "Maths", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Hindi (b) Science (c) Maths (d) Art
3. 3.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 10 (c) 2 (d) 1
4. 4.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
5. 5.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
6. 6.💾 What number does this code show?
   let notes = ["Science", "Hindi", "Sports"];
   notes.push("Music");
   show(notes.length);
7. 7.💾 What does this code show? (Positions start at 0.)
   let notes = ["Science", "Maths", "Sports"];
   show(notes[2]); (a) Science (b) Sports (c) Maths
8. 8.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
9. 9.💾 What number does this code show?
   let lives = 4;
   lives = lives - 3;
   lives = lives + 3;
   show(lives);
10. 10.Which of these fits saving in the cloud? (a) a shared to-do list (b) notes to read offline (c) the sound on/off setting (d) your last game level
11. 11.True or false: notes to read offline fits saving on the phone. (a) False (b) True
12. 12.Which of these fits saving on the phone? (a) a draft you are typing (b) chat messages to friends (c) a shared to-do list (d) a class leaderboard
13. 13.💾 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
14. 14.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) your last game level (d) a class leaderboard
15. 15.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
16. 16.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Stars", "Kites", "Rain", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Kites (d) Stars
17. 17.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) a shared to-do list (d) notes to read offline
18. 18.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Stars", "Kites", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Stars (c) Monsoon (d) Rain
19. 19.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Arjun", "Aman", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Arjun (c) Zoya (d) Kabir
20. 20.Which of these fits saving on the phone? (a) photos on two devices (b) your last game level (c) chat messages to friends (d) a shared to-do list
21. 21.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
22. 22.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Ocean", "Sunrise", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Monsoon (d) Sunrise
23. 23.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Rain", "Sunrise", "Kites"];
    show(songs[1]); (a) Sunrise (b) Stars (c) Rain (d) Kites
24. 24.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
25. 25.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a type of screen (d) a picture
26. 26.💾 What number does this code show?
    let songs = ["Sunrise", "Rain", "Monsoon", "Stars"];
    songs.push("Kites");
    show(songs.length);
27. 27.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Kabir", "Aman", "Riya"];
    show(friends[3]); (a) Aman (b) Riya (c) Kabir (d) Meera
28. 28.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
29. 29.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Sunrise", "Rain", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Sunrise (c) Stars (d) Rain
31. 31.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Music", "Science", "Maths", "Sports"];
    show(notes[0]); (a) Music (b) Science (c) Hindi (d) Maths
32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Riya", "Zoya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Aman (c) Zoya (d) Riya
33. 33.💾 What number does this code show?
    let coins = 9;
    coins = coins - 4;
    coins = coins + 5;
    show(coins);
34. 34.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
35. 35.True or false: your last game level fits saving on the phone. (a) False (b) True
36. 36.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Aman", "Riya", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Aman (c) Kabir (d) Riya
37. 37.💾 What number does this code show?
    let notes = ["Science", "Maths", "Hindi"];
    notes.push("Art");
    notes.push("Music");
    show(notes.length);
38. 38.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
39. 39.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) in the cloud (b) on the phone
40. 40.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Hindi", "Art"];
    show(notes[0]); (a) Hindi (b) Art (c) Science

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