App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 379 · 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", "Rain", "Kites"];
   songs.push("Stars");
   songs.push("Sunrise");
   show(songs.length);
2. 2.💾 pop() takes off the last item. What does this code show?
   let notes = ["Hindi", "Sports", "Art", "Maths"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Hindi (c) Art (d) Maths
3. 3.Which of these fits saving on the phone? (a) your last game level (b) chat messages to friends (c) a class leaderboard (d) photos on two devices
4. 4.💾 pop() takes off the last item. What does this code show?
   let songs = ["Kites", "Rain", "Sunrise", "Monsoon"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Rain (b) Kites (c) Sunrise (d) Monsoon
5. 5.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
6. 6.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) skip the internet (c) never need a password (d) use it on any device
7. 7.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
8. 8.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
9. 9.💾 pop() takes off the last item. What does this code show?
   let friends = ["Zoya", "Arjun", "Kabir", "Riya", "Aman"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Zoya (b) Arjun (c) Kabir (d) Riya
10. 10.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Meera", "Riya", "Aman"];
    show(friends[0]); (a) Aman (b) Zoya (c) Riya (d) Meera
11. 11.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
12. 12.💾 Which can hold many values in order? (a) a button (b) a single number (c) a switch (d) a list
13. 13.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Music", "Maths", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Hindi (c) Science (d) Maths
14. 14.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
15. 15.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Maths", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Sports
16. 16.True or false: your last game level fits saving in the cloud. (a) True (b) False
17. 17.💾 What number does this code show?
    let coins = 5;
    coins = coins - 5;
    coins = coins + 4;
    show(coins);
18. 18.💾 What number does this code show?
    let coins = 3;
    coins = coins - 3;
    coins = coins + 4;
    show(coins);
19. 19.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
20. 20.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
21. 21.💾 What number does this code show?
    let notes = ["Science", "Maths", "Art", "Sports"];
    notes.push("Music");
    show(notes.length);
22. 22.💾 What number does this code show?
    let coins = 4;
    coins = coins - 4;
    coins = coins + 2;
    show(coins);
23. 23.Which of these fits saving in the cloud? (a) a draft you are typing (b) chat messages to friends (c) notes to read offline (d) the sound on/off setting
24. 24.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the app is closed (c) the screen turns off (d) the phone is lost
25. 25.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
26. 26.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Zoya", "Kabir", "Meera", "Riya"];
    show(friends[1]); (a) Meera (b) Arjun (c) Kabir (d) Zoya
27. 27.💾 What number does this code show?
    let notes = ["Music", "Hindi"];
    notes.push("Sports");
    notes.push("Art");
    show(notes.length);
28. 28.💾 What number does this code show?
    let notes = ["Science", "Sports", "Music", "Art"];
    notes.push("Maths");
    show(notes.length);
29. 29.💾 Which works with no internet at all? (a) a shared chat (b) a cloud leaderboard (c) a cloud backup (d) data saved on the phone
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Stars", "Ocean", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Stars (c) Sunrise (d) Ocean
31. 31.💾 What number does this code show?
    let notes = ["Hindi", "Art", "Maths"];
    notes.push("Music");
    notes.push("Science");
    show(notes.length);
32. 32.💾 What is a variable? (a) a picture (b) a phone setting (c) a type of screen (d) a named box for a value
33. 33.True or false: notes to read offline fits saving on the phone. (a) True (b) False
34. 34.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
35. 35.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) photos on two devices (d) the sound on/off setting
36. 36.Which of these fits saving in the cloud? (a) a shared to-do list (b) a draft you are typing (c) the sound on/off setting (d) your last game level
37. 37.💾 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
38. 38.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
39. 39.💾 What number does this code show?
    let score = 4;
    score = score - 3;
    score = score + 4;
    show(score);
40. 40.💾 What number does this code show?
    let coins = 5;
    coins = coins - 3;
    coins = coins + 4;
    show(coins);

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