App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 699 · 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.True or false: a shared to-do list fits saving in the cloud. (a) False (b) True
2. 2.Which of these fits saving in the cloud? (a) chat messages to friends (b) notes to read offline (c) a draft you are typing (d) your last game level
3. 3.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
4. 4.💾 pop() takes off the last item. What does this code show?
   let notes = ["Music", "Maths", "Science", "Hindi", "Art"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Science (b) Maths (c) Music (d) Hindi
5. 5.💾 What is a variable? (a) a named box for a value (b) a picture (c) a phone setting (d) a type of screen
6. 6.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
8. 8.💾 pop() takes off the last item. What does this code show?
   let notes = ["Art", "Science", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Art (b) Sports (c) Science
9. 9.Which of these fits saving on the phone? (a) your last game level (b) a shared to-do list (c) a class leaderboard (d) photos on two devices
10. 10.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
11. 11.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) a draft you are typing (d) photos on two devices
12. 12.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Monsoon", "Kites", "Rain", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Monsoon (c) Kites (d) Sunrise
13. 13.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Sunrise", "Rain", "Monsoon", "Stars"];
    show(songs[0]); (a) Rain (b) Sunrise (c) Kites (d) Monsoon
14. 14.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
15. 15.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the screen turns off (c) the phone is lost (d) the app is closed
16. 16.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Meera", "Riya", "Aman", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Meera (c) Riya (d) Aman
17. 17.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
18. 18.Which of these fits saving in the cloud? (a) a class leaderboard (b) your last game level (c) the sound on/off setting (d) a draft you are typing
19. 19.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
20. 20.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 10 (d) 2
21. 21.💾 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
22. 22.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
23. 23.💾 Saving data in the cloud lets you ___. (a) never need a password (b) use it on any device (c) skip the internet (d) shrink the app
24. 24.💾 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
25. 25.💾 What number does this code show?
    let friends = ["Aman", "Kabir"];
    friends.push("Arjun");
    friends.push("Riya");
    show(friends.length);
26. 26.💾 Which can hold many values in order? (a) a single number (b) a switch (c) a button (d) a list
27. 27.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
28. 28.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
29. 29.True or false: your last game level fits saving in the cloud. (a) True (b) False
30. 30.💾 What number does this code show?
    let friends = ["Aman", "Arjun"];
    friends.push("Kabir");
    show(friends.length);
31. 31.💾 What number does this code show?
    let songs = ["Monsoon", "Stars", "Rain"];
    songs.push("Kites");
    show(songs.length);
32. 32.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a shared chat (c) data saved on the phone (d) a cloud backup
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Maths", "Music", "Hindi", "Sports"];
    show(notes[0]); (a) Hindi (b) Music (c) Science (d) Maths
34. 34.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Sports", "Science"];
    show(notes[0]); (a) Sports (b) Science (c) Maths
35. 35.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Art", "Hindi", "Music"];
    show(notes[1]); (a) Art (b) Sports (c) Hindi (d) Music
36. 36.💾 What number does this code show?
    let notes = ["Music", "Maths", "Art", "Sports"];
    notes.push("Hindi");
    notes.push("Science");
    show(notes.length);
37. 37.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
38. 38.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Hindi", "Sports", "Science"];
    show(notes[4]); (a) Maths (b) Science (c) Hindi (d) Art
39. 39.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Music", "Hindi", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Music (c) Sports (d) Science
40. 40.💾 What number does this code show?
    let points = 6;
    points = points - 1;
    points = points + 2;
    show(points);

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