App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 51 · 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.💾 pop() takes off the last item. What does this code show?
   let notes = ["Science", "Art", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Science (c) Art
2. 2.True or false: photos on two devices fits saving on the phone. (a) False (b) True
3. 3.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 0 (d) 2
4. 4.💾 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
5. 5.💾 Which can hold many values in order? (a) a switch (b) a list (c) a single number (d) a button
6. 6.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
7. 7.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
8. 8.💾 What does this code show? (Positions start at 0.)
   let songs = ["Ocean", "Rain", "Stars", "Monsoon"];
   show(songs[1]); (a) Rain (b) Monsoon (c) Stars (d) Ocean
9. 9.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.Which of these fits saving in the cloud? (a) your last game level (b) chat messages to friends (c) notes to read offline (d) a draft you are typing
11. 11.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Arjun", "Zoya", "Aman"];
    show(friends[0]); (a) Zoya (b) Arjun (c) Kabir (d) Aman
12. 12.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
13. 13.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) your last game level (d) photos on two devices
14. 14.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Arjun", "Kabir"];
    show(friends[0]); (a) Arjun (b) Kabir (c) Meera
15. 15.💾 What number does this code show?
    let notes = ["Science", "Hindi"];
    notes.push("Art");
    notes.push("Music");
    show(notes.length);
16. 16.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Kites", "Ocean", "Sunrise", "Monsoon"];
    show(songs[3]); (a) Rain (b) Ocean (c) Kites (d) Sunrise
17. 17.💾 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
18. 18.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Science", "Maths", "Music", "Hindi"];
    show(notes[3]); (a) Music (b) Sports (c) Science (d) Maths
19. 19.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
20. 20.💾 What number does this code show?
    let notes = ["Art", "Sports"];
    notes.push("Music");
    show(notes.length);
21. 21.Which of these fits saving on the phone? (a) a shared to-do list (b) notes to read offline (c) photos on two devices (d) a class leaderboard
22. 22.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) the sound on/off setting (d) photos on two devices
23. 23.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Maths", "Art", "Sports"];
    show(notes[3]); (a) Sports (b) Art (c) Maths (d) Science
24. 24.💾 What number does this code show?
    let friends = ["Zoya", "Kabir"];
    friends.push("Arjun");
    show(friends.length);
25. 25.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) use it on any device (c) never need a password (d) skip the internet
26. 26.💾 What number does this code show?
    let friends = ["Kabir", "Meera"];
    friends.push("Riya");
    friends.push("Arjun");
    show(friends.length);
27. 27.💾 What number does this code show?
    let coins = 5;
    coins = coins - 2;
    coins = coins + 1;
    show(coins);
28. 28.💾 What number does this code show?
    let friends = ["Aman", "Meera", "Zoya"];
    friends.push("Riya");
    friends.push("Kabir");
    show(friends.length);
29. 29.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Sunrise"];
    show(songs[2]); (a) Kites (b) Sunrise (c) Monsoon
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Stars (c) Monsoon
31. 31.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Kites", "Ocean", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Sunrise (c) Stars (d) Ocean
32. 32.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
33. 33.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
34. 34.💾 What number does this code show?
    let songs = ["Stars", "Ocean", "Kites", "Monsoon"];
    songs.push("Sunrise");
    show(songs.length);
35. 35.💾 What number does this code show?
    let score = 8;
    score = score - 8;
    score = score + 4;
    show(score);
36. 36.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Hindi", "Music", "Science"];
    show(notes[0]); (a) Science (b) Music (c) Hindi (d) Maths
37. 37.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Aman", "Kabir"];
    show(friends[1]); (a) Zoya (b) Aman (c) Kabir
38. 38.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Music"];
    show(notes[2]); (a) Science (b) Art (c) Music
39. 39.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
40. 40.Which of these fits saving on the phone? (a) chat messages to friends (b) a shared to-do list (c) a class leaderboard (d) a draft you are typing

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