App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 346 · 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 = ["Monsoon", "Stars"];
   songs.push("Ocean");
   songs.push("Kites");
   show(songs.length);
2. 2.💾 What number does this code show?
   let friends = ["Kabir", "Meera", "Arjun"];
   friends.push("Riya");
   friends.push("Zoya");
   show(friends.length);
3. 3.💾 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
4. 4.💾 What number does this code show?
   let friends = ["Aman", "Zoya", "Riya", "Meera"];
   friends.push("Arjun");
   friends.push("Kabir");
   show(friends.length);
5. 5.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
6. 6.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) chat messages to friends (d) your last game level
7. 7.💾 What number does this code show?
   let score = 4;
   score = score - 1;
   score = score + 4;
   show(score);
8. 8.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
9. 9.💾 What number does this code show?
   let notes = ["Science", "Hindi"];
   notes.push("Sports");
   show(notes.length);
10. 10.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
11. 11.💾 What number does this code show?
    let songs = ["Monsoon", "Rain"];
    songs.push("Stars");
    show(songs.length);
12. 12.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
13. 13.Which of these fits saving on the phone? (a) photos on two devices (b) notes to read offline (c) a shared to-do list (d) a class leaderboard
14. 14.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Maths", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Hindi
15. 15.💾 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
16. 16.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
17. 17.💾 Which can hold many values in order? (a) a single number (b) a switch (c) a list (d) a button
18. 18.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
19. 19.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Sports", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Hindi (c) Art
20. 20.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
21. 21.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Stars"];
    show(songs[2]); (a) Kites (b) Sunrise (c) Stars
22. 22.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) a shared to-do list (d) a draft you are typing
23. 23.💾 What is a variable? (a) a named box for a value (b) a type of screen (c) a picture (d) a phone setting
24. 24.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Ocean"];
    show(songs[1]); (a) Rain (b) Ocean (c) Monsoon
25. 25.💾 Which works with no internet at all? (a) a cloud backup (b) data saved on the phone (c) a cloud leaderboard (d) a shared chat
26. 26.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Riya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Aman (c) Riya
27. 27.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
28. 28.💾 What number does this code show?
    let notes = ["Music", "Art", "Hindi"];
    notes.push("Maths");
    show(notes.length);
29. 29.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
30. 30.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
31. 31.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) shrink the app (c) never need a password (d) skip the internet
32. 32.💾 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
33. 33.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the screen turns off (c) the app is closed (d) you send a message
34. 34.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
35. 35.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) the sound on/off setting
36. 36.Which of these fits saving on the phone? (a) a class leaderboard (b) your last game level (c) chat messages to friends (d) a shared to-do list
37. 37.💾 What number does this code show?
    let songs = ["Kites", "Rain", "Stars", "Ocean"];
    songs.push("Monsoon");
    show(songs.length);
38. 38.💾 What number does this code show?
    let notes = ["Hindi", "Music", "Sports", "Science"];
    notes.push("Maths");
    show(notes.length);
39. 39.💾 What number does this code show?
    let lives = 6;
    lives = lives - 1;
    lives = lives + 4;
    show(lives);
40. 40.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Maths (c) Hindi

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