App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 641 · 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 friends = ["Arjun", "Aman"];
   friends.push("Riya");
   show(friends.length);
2. 2.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a named box for a value (d) a picture
3. 3.💾 What number does this code show?
   let notes = ["Science", "Maths", "Music"];
   notes.push("Hindi");
   show(notes.length);
4. 4.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
5. 5.💾 What number does this code show?
   let songs = ["Sunrise", "Ocean", "Monsoon"];
   songs.push("Stars");
   show(songs.length);
6. 6.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) photos on two devices (d) notes to read offline
7. 7.💾 What number does this code show?
   let notes = ["Maths", "Sports", "Art", "Science"];
   notes.push("Hindi");
   notes.push("Music");
   show(notes.length);
8. 8.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.💾 What number does this code show?
   let stars = 9;
   stars = stars - 4;
   stars = stars + 4;
   show(stars);
10. 10.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the app is closed (c) the screen turns off (d) you send a message
11. 11.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a list (d) a button
12. 12.💾 What number does this code show?
    let notes = ["Maths", "Sports", "Music"];
    notes.push("Science");
    show(notes.length);
13. 13.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
14. 14.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
15. 15.💾 What number does this code show?
    let songs = ["Kites", "Ocean", "Sunrise", "Stars"];
    songs.push("Rain");
    show(songs.length);
16. 16.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
17. 17.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Ocean", "Kites", "Monsoon", "Stars"];
    show(songs[2]); (a) Sunrise (b) Monsoon (c) Kites (d) Ocean
18. 18.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Zoya", "Meera", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Aman (c) Riya (d) Meera
19. 19.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
20. 20.💾 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
21. 21.Which of these fits saving in the cloud? (a) chat messages to friends (b) your last game level (c) a draft you are typing (d) notes to read offline
22. 22.💾 What number does this code show?
    let stars = 9;
    stars = stars - 9;
    stars = stars + 5;
    show(stars);
23. 23.True or false: photos on two devices fits saving on the phone. (a) True (b) False
24. 24.💾 What number does this code show?
    let score = 3;
    score = score - 1;
    score = score + 2;
    show(score);
25. 25.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
26. 26.💾 Which works with no internet at all? (a) a cloud leaderboard (b) data saved on the phone (c) a cloud backup (d) a shared chat
27. 27.💾 What number does this code show?
    let friends = ["Arjun", "Zoya", "Kabir", "Riya"];
    friends.push("Meera");
    show(friends.length);
28. 28.💾 What number does this code show?
    let notes = ["Science", "Hindi", "Art"];
    notes.push("Music");
    show(notes.length);
29. 29.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Riya", "Kabir", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Riya (d) Meera
30. 30.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) skip the internet (d) use it on any device
31. 31.💾 What number does this code show?
    let lives = 8;
    lives = lives - 7;
    lives = lives + 3;
    show(lives);
32. 32.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Kabir"];
    show(friends[0]); (a) Riya (b) Kabir (c) Arjun
33. 33.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
34. 34.Which of these fits saving on the phone? (a) a draft you are typing (b) a class leaderboard (c) photos on two devices (d) a shared to-do list
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Ocean", "Monsoon", "Kites", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Rain (c) Kites (d) Ocean
36. 36.💾 What number does this code show?
    let friends = ["Arjun", "Aman"];
    friends.push("Zoya");
    friends.push("Riya");
    show(friends.length);
37. 37.Which of these fits saving in the cloud? (a) notes to read offline (b) photos on two devices (c) your last game level (d) the sound on/off setting
38. 38.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
39. 39.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
40. 40.💾 What number does this code show?
    let notes = ["Hindi", "Sports", "Music", "Art"];
    notes.push("Maths");
    show(notes.length);

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