App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 97 · 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 songs = ["Rain", "Ocean", "Monsoon"];
   songs.push("Sunrise");
   songs.push("Kites");
   show(songs.length);
2. 2.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
3. 3.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a type of screen (d) a picture
4. 4.💾 What number does this code show?
   let notes = ["Maths", "Music"];
   notes.push("Sports");
   show(notes.length);
5. 5.💾 What number does this code show?
   let score = 8;
   score = score - 4;
   score = score + 3;
   show(score);
6. 6.💾 What number does this code show?
   let notes = ["Art", "Maths", "Hindi", "Science"];
   notes.push("Sports");
   show(notes.length);
7. 7.💾 What number does this code show?
   let friends = ["Aman", "Meera"];
   friends.push("Arjun");
   show(friends.length);
8. 8.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.💾 What number does this code show?
   let songs = ["Kites", "Ocean", "Monsoon"];
   songs.push("Rain");
   show(songs.length);
10. 10.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) a draft you are typing (d) a class leaderboard
11. 11.Which of these fits saving on the phone? (a) a shared to-do list (b) chat messages to friends (c) notes to read offline (d) a class leaderboard
12. 12.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Maths", "Art"];
    show(notes[1]); (a) Art (b) Maths (c) Science
13. 13.💾 What number does this code show?
    let score = 4;
    score = score - 4;
    score = score + 2;
    show(score);
14. 14.💾 What number does this code show?
    let stars = 3;
    stars = stars - 2;
    stars = stars + 4;
    show(stars);
15. 15.💾 What number does this code show?
    let friends = ["Zoya", "Arjun", "Meera", "Riya"];
    friends.push("Aman");
    show(friends.length);
16. 16.True or false: your last game level fits saving on the phone. (a) True (b) False
17. 17.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
18. 18.Which of these fits saving on the phone? (a) a class leaderboard (b) a shared to-do list (c) your last game level (d) chat messages to friends
19. 19.💾 Which can hold many values in order? (a) a button (b) a single number (c) a list (d) a switch
20. 20.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Kabir", "Arjun"];
    show(friends[2]); (a) Riya (b) Kabir (c) Arjun
21. 21.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Art", "Music", "Hindi"];
    show(notes[3]); (a) Music (b) Science (c) Art (d) Hindi
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.💾 What number does this code show?
    let songs = ["Stars", "Kites"];
    songs.push("Sunrise");
    songs.push("Monsoon");
    show(songs.length);
24. 24.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
25. 25.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) on the phone (b) in the cloud
26. 26.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) you send a message (c) the app is closed (d) the screen turns off
27. 27.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 2 (d) 0
28. 28.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) skip the internet (c) shrink the app (d) never need a password
29. 29.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Art"];
    show(notes[2]); (a) Music (b) Art (c) Maths
30. 30.💾 What number does this code show?
    let songs = ["Sunrise", "Monsoon", "Ocean", "Stars"];
    songs.push("Kites");
    show(songs.length);
31. 31.Which of these fits saving in the cloud? (a) photos on two devices (b) your last game level (c) a draft you are typing (d) notes to read offline
32. 32.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
33. 33.💾 What number does this code show?
    let notes = ["Sports", "Hindi", "Science", "Art"];
    notes.push("Maths");
    show(notes.length);
34. 34.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Kabir", "Meera", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Aman (c) Kabir (d) Meera
35. 35.💾 What number does this code show?
    let friends = ["Riya", "Aman"];
    friends.push("Arjun");
    friends.push("Kabir");
    show(friends.length);
36. 36.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
37. 37.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
38. 38.💾 What number does this code show?
    let notes = ["Art", "Science", "Maths", "Hindi"];
    notes.push("Sports");
    show(notes.length);
39. 39.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Art", "Sports", "Music", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Art (c) Music (d) Sports
40. 40.💾 What number does this code show?
    let notes = ["Maths", "Art", "Sports"];
    notes.push("Hindi");
    show(notes.length);

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