App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 818 · 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 coins = 5;
   coins = coins - 4;
   coins = coins + 3;
   show(coins);
2. 2.💾 pop() takes off the last item. What does this code show?
   let friends = ["Arjun", "Meera", "Aman", "Riya", "Zoya"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Riya (b) Arjun (c) Aman (d) Meera
3. 3.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
4. 4.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 2 (d) 10
5. 5.💾 What number does this code show?
   let notes = ["Maths", "Hindi", "Sports"];
   notes.push("Music");
   notes.push("Art");
   show(notes.length);
6. 6.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
8. 8.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Science", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Art (c) Music
11. 11.💾 What is a variable? (a) a named box for a value (b) a phone setting (c) a type of screen (d) a picture
12. 12.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
13. 13.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
14. 14.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Rain", "Sunrise", "Monsoon"];
    show(songs[1]); (a) Rain (b) Monsoon (c) Ocean (d) Sunrise
15. 15.💾 What number does this code show?
    let notes = ["Music", "Science"];
    notes.push("Sports");
    show(notes.length);
16. 16.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Science", "Music"];
    show(notes[0]); (a) Art (b) Maths (c) Science (d) Music
17. 17.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Sports", "Maths", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Maths (c) Sports (d) Science
18. 18.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Sports", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Maths (c) Sports
19. 19.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Music"];
    show(notes[1]); (a) Hindi (b) Music (c) Art
20. 20.💾 What number does this code show?
    let notes = ["Sports", "Hindi"];
    notes.push("Art");
    show(notes.length);
21. 21.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
22. 22.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Rain", "Stars", "Kites"];
    show(songs[3]); (a) Rain (b) Stars (c) Ocean (d) Kites
23. 23.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
24. 24.💾 Which works with no internet at all? (a) a shared chat (b) a cloud backup (c) a cloud leaderboard (d) data saved on the phone
25. 25.💾 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
26. 26.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
27. 27.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the app is closed (c) the phone is lost (d) you send a message
28. 28.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) the sound on/off setting (d) chat messages to friends
30. 30.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) your last game level (d) chat messages to friends
31. 31.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Monsoon", "Ocean", "Kites"];
    show(songs[1]); (a) Stars (b) Ocean (c) Kites (d) Monsoon
32. 32.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Zoya", "Meera", "Riya", "Kabir"];
    show(friends[4]); (a) Meera (b) Arjun (c) Zoya (d) Kabir
33. 33.💾 What number does this code show?
    let score = 6;
    score = score - 6;
    score = score + 3;
    show(score);
34. 34.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) use it on any device (d) never need a password
35. 35.💾 What number does this code show?
    let notes = ["Art", "Hindi"];
    notes.push("Music");
    notes.push("Sports");
    show(notes.length);
36. 36.💾 What number does this code show?
    let songs = ["Kites", "Stars", "Ocean", "Monsoon"];
    songs.push("Rain");
    songs.push("Sunrise");
    show(songs.length);
37. 37.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) a class leaderboard (d) your last game level
38. 38.💾 What number does this code show?
    let notes = ["Art", "Hindi"];
    notes.push("Maths");
    notes.push("Science");
    show(notes.length);
39. 39.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Hindi", "Sports"];
    show(notes[1]); (a) Art (b) Music (c) Hindi (d) Sports
40. 40.True or false: notes to read offline fits saving on the phone. (a) True (b) False

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