App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 961 · 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 = ["Music", "Maths"];
   notes.push("Sports");
   show(notes.length);
2. 2.💾 What is a variable? (a) a type of screen (b) a phone setting (c) a picture (d) a named box for a value
3. 3.💾 What does this code show? (Positions start at 0.)
   let friends = ["Zoya", "Meera", "Aman", "Kabir", "Riya"];
   show(friends[4]); (a) Meera (b) Zoya (c) Riya (d) Aman
4. 4.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) chat messages to friends
5. 5.True or false: photos on two devices fits saving on the phone. (a) False (b) True
6. 6.💾 What number does this code show?
   let stars = 5;
   stars = stars - 2;
   stars = stars + 4;
   show(stars);
7. 7.💾 What does this code show? (Positions start at 0.)
   let notes = ["Maths", "Science", "Hindi", "Sports", "Music"];
   show(notes[4]); (a) Hindi (b) Science (c) Music (d) Maths
8. 8.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
9. 9.💾 Which can hold many values in order? (a) a list (b) a single number (c) a button (d) a switch
10. 10.💾 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
11. 11.💾 What number does this code show?
    let notes = ["Art", "Hindi", "Music"];
    notes.push("Sports");
    notes.push("Maths");
    show(notes.length);
12. 12.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
13. 13.💾 What number does this code show?
    let stars = 8;
    stars = stars - 7;
    stars = stars + 3;
    show(stars);
14. 14.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the app is closed (c) you send a message (d) the screen turns off
15. 15.💾 What number does this code show?
    let friends = ["Kabir", "Meera", "Zoya"];
    friends.push("Riya");
    friends.push("Aman");
    show(friends.length);
16. 16.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
17. 17.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) data saved on the phone (d) a shared chat
18. 18.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Stars", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Sunrise (b) Kites (c) Stars
19. 19.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Rain", "Ocean"];
    show(songs[0]); (a) Sunrise (b) Rain (c) Ocean
20. 20.💾 What number does this code show?
    let score = 4;
    score = score - 2;
    score = score + 1;
    show(score);
21. 21.True or false: your last game level fits saving in the cloud. (a) False (b) True
22. 22.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Hindi", "Science", "Sports"];
    show(notes[1]); (a) Sports (b) Hindi (c) Science (d) Music
23. 23.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
24. 24.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
25. 25.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
26. 26.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a draft you are typing (d) photos on two devices
27. 27.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 2 (c) 1 (d) 10
28. 28.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.💾 What number does this code show?
    let lives = 8;
    lives = lives - 8;
    lives = lives + 2;
    show(lives);
30. 30.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) on the phone (b) in the cloud
31. 31.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Riya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Riya (c) Meera
33. 33.Which of these fits saving on the phone? (a) a draft you are typing (b) a class leaderboard (c) a shared to-do list (d) photos on two devices
34. 34.💾 What number does this code show?
    let stars = 7;
    stars = stars - 2;
    stars = stars + 1;
    show(stars);
35. 35.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
36. 36.True or false: your last game level fits saving on the phone. (a) True (b) False
37. 37.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
38. 38.💾 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
39. 39.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Maths", "Art", "Hindi", "Science"];
    show(notes[1]); (a) Maths (b) Music (c) Hindi (d) Art
40. 40.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) a shared to-do list (d) the sound on/off setting

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