App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 195 · 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 does this code show? (Positions start at 0.)
   let notes = ["Sports", "Art", "Maths", "Science"];
   show(notes[3]); (a) Maths (b) Art (c) Sports (d) Science
2. 2.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
3. 3.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) notes to read offline (d) a shared to-do list
4. 4.💾 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
5. 5.Which of these fits saving in the cloud? (a) your last game level (b) a shared to-do list (c) notes to read offline (d) the sound on/off setting
6. 6.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) a class leaderboard (d) your last game level
7. 7.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the phone is lost (c) the app is closed (d) you send a message
8. 8.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) photos on two devices (d) notes to read offline
9. 9.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.💾 What number does this code show?
    let friends = ["Aman", "Riya"];
    friends.push("Meera");
    friends.push("Kabir");
    show(friends.length);
11. 11.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
12. 12.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
13. 13.💾 What number does this code show?
    let notes = ["Music", "Hindi", "Sports", "Art"];
    notes.push("Science");
    notes.push("Maths");
    show(notes.length);
14. 14.💾 What number does this code show?
    let points = 7;
    points = points - 6;
    points = points + 4;
    show(points);
15. 15.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 10 (c) 1 (d) 2
16. 16.💾 What number does this code show?
    let notes = ["Art", "Science", "Sports", "Hindi"];
    notes.push("Music");
    notes.push("Maths");
    show(notes.length);
17. 17.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
18. 18.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
19. 19.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
20. 20.True or false: notes to read offline fits saving on the phone. (a) True (b) False
21. 21.Which of these fits saving in the cloud? (a) chat messages to friends (b) your last game level (c) notes to read offline (d) a draft you are typing
22. 22.💾 What number does this code show?
    let lives = 4;
    lives = lives - 1;
    lives = lives + 1;
    show(lives);
23. 23.💾 What number does this code show?
    let friends = ["Kabir", "Aman", "Meera", "Arjun"];
    friends.push("Riya");
    show(friends.length);
24. 24.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Science", "Sports"];
    show(notes[1]); (a) Sports (b) Science (c) Hindi
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.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
27. 27.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
28. 28.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
29. 29.💾 What number does this code show?
    let songs = ["Stars", "Kites", "Ocean"];
    songs.push("Rain");
    show(songs.length);
30. 30.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a picture (d) a type of screen
31. 31.💾 What number does this code show?
    let notes = ["Maths", "Music", "Art"];
    notes.push("Sports");
    notes.push("Science");
    show(notes.length);
32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Kabir", "Meera", "Aman", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Zoya (d) Kabir
33. 33.💾 What number does this code show?
    let score = 8;
    score = score - 3;
    score = score + 5;
    show(score);
34. 34.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
35. 35.💾 What number does this code show?
    let notes = ["Art", "Sports"];
    notes.push("Science");
    show(notes.length);
36. 36.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Stars", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Ocean (c) Rain
37. 37.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Rain", "Stars", "Ocean"];
    show(songs[4]); (a) Sunrise (b) Rain (c) Ocean (d) Kites
38. 38.💾 What number does this code show?
    let friends = ["Aman", "Kabir", "Meera", "Zoya"];
    friends.push("Riya");
    show(friends.length);
39. 39.💾 What number does this code show?
    let friends = ["Kabir", "Arjun"];
    friends.push("Meera");
    show(friends.length);
40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Rain", "Ocean", "Sunrise", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Kites (c) Sunrise (d) Ocean

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