App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 685 · 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 notes = ["Sports", "Hindi", "Maths", "Art"];
   notes.push("Music");
   notes.push("Science");
   show(notes.length);
2. 2.💾 What is a variable? (a) a type of screen (b) a picture (c) a phone setting (d) a named box for a value
3. 3.💾 What number does this code show?
   let stars = 7;
   stars = stars - 2;
   stars = stars + 5;
   show(stars);
4. 4.💾 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
5. 5.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Art", "Hindi"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Maths (b) Hindi (c) Art
6. 6.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.💾 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
8. 8.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
9. 9.💾 pop() takes off the last item. What does this code show?
   let notes = ["Science", "Music", "Maths"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Science (b) Maths (c) Music
10. 10.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) a shared to-do list (d) your last game level
11. 11.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Kites", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Sunrise (c) Kites
12. 12.Which of these fits saving on the phone? (a) notes to read offline (b) chat messages to friends (c) photos on two devices (d) a shared to-do list
13. 13.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 1 (c) 0 (d) 10
14. 14.💾 What number does this code show?
    let notes = ["Maths", "Music"];
    notes.push("Art");
    notes.push("Science");
    show(notes.length);
15. 15.💾 What number does this code show?
    let songs = ["Ocean", "Stars"];
    songs.push("Kites");
    show(songs.length);
16. 16.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
17. 17.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
18. 18.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Science", "Music"];
    show(notes[1]); (a) Hindi (b) Music (c) Science
19. 19.💾 What number does this code show?
    let songs = ["Sunrise", "Kites", "Rain"];
    songs.push("Ocean");
    show(songs.length);
20. 20.💾 What number does this code show?
    let notes = ["Music", "Maths"];
    notes.push("Science");
    notes.push("Art");
    show(notes.length);
21. 21.💾 What does this code show? (Positions start at 0.)
    let songs = ["Rain", "Ocean", "Kites", "Sunrise"];
    show(songs[1]); (a) Kites (b) Rain (c) Sunrise (d) Ocean
22. 22.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
23. 23.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
24. 24.💾 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
25. 25.💾 Which can hold many values in order? (a) a button (b) a single number (c) a switch (d) a list
26. 26.💾 What number does this code show?
    let stars = 5;
    stars = stars - 2;
    stars = stars + 1;
    show(stars);
27. 27.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Meera", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Meera (c) Kabir
28. 28.True or false: photos on two devices fits saving on the phone. (a) True (b) False
29. 29.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) chat messages to friends (d) the sound on/off setting
30. 30.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
31. 31.💾 What number does this code show?
    let lives = 8;
    lives = lives - 6;
    lives = lives + 4;
    show(lives);
32. 32.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
33. 33.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Riya", "Meera", "Aman", "Arjun"];
    show(friends[2]); (a) Riya (b) Meera (c) Kabir (d) Aman
34. 34.💾 pop() takes off the last item. What does this code show?
    let songs = ["Monsoon", "Rain", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Rain (c) Stars
35. 35.💾 What number does this code show?
    let lives = 9;
    lives = lives - 5;
    lives = lives + 1;
    show(lives);
36. 36.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) notes to read offline (d) a class leaderboard
37. 37.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Ocean", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Sunrise (c) Ocean
38. 38.💾 What number does this code show?
    let friends = ["Kabir", "Aman", "Riya", "Arjun"];
    friends.push("Meera");
    friends.push("Zoya");
    show(friends.length);
39. 39.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) a draft you are typing (d) chat messages to friends
40. 40.💾 What number does this code show?
    let notes = ["Art", "Maths", "Hindi"];
    notes.push("Science");
    show(notes.length);

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