App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 141 · 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 is a variable? (a) a phone setting (b) a picture (c) a type of screen (d) a named box for a value
2. 2.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
3. 3.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the phone is lost (d) the app is closed
5. 5.💾 What number does this code show?
   let coins = 6;
   coins = coins - 1;
   coins = coins + 5;
   show(coins);
6. 6.💾 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
7. 7.💾 What number does this code show?
   let score = 7;
   score = score - 2;
   score = score + 4;
   show(score);
8. 8.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
9. 9.💾 What number does this code show?
   let songs = ["Ocean", "Sunrise"];
   songs.push("Rain");
   show(songs.length);
10. 10.💾 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
11. 11.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Sports", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Hindi (c) Sports
12. 12.True or false: your last game level fits saving on the phone. (a) True (b) False
13. 13.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
14. 14.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
15. 15.Which of these fits saving in the cloud? (a) a draft you are typing (b) notes to read offline (c) a class leaderboard (d) the sound on/off setting
16. 16.True or false: notes to read offline fits saving on the phone. (a) False (b) True
17. 17.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
18. 18.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Kabir", "Aman", "Arjun", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Zoya (c) Kabir (d) Arjun
19. 19.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Music", "Maths", "Science", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Maths (c) Art (d) Music
20. 20.True or false: your last game level fits saving in the cloud. (a) True (b) False
21. 21.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) chat messages to friends (d) notes to read offline
22. 22.Which of these fits saving in the cloud? (a) notes to read offline (b) your last game level (c) a shared to-do list (d) the sound on/off setting
23. 23.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Kabir", "Aman", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Meera (c) Arjun (d) Aman
24. 24.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
25. 25.💾 What number does this code show?
    let coins = 9;
    coins = coins - 3;
    coins = coins + 2;
    show(coins);
26. 26.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
27. 27.💾 What number does this code show?
    let notes = ["Music", "Sports", "Science"];
    notes.push("Hindi");
    show(notes.length);
28. 28.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Sunrise", "Rain"];
    show(songs[0]); (a) Monsoon (b) Sunrise (c) Rain (d) Kites
29. 29.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Music", "Art"];
    show(notes[2]); (a) Art (b) Music (c) Science
30. 30.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
31. 31.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Riya", "Kabir", "Meera"];
    show(friends[3]); (a) Kabir (b) Meera (c) Zoya (d) Riya
32. 32.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Sunrise", "Ocean", "Rain"];
    show(songs[3]); (a) Sunrise (b) Rain (c) Monsoon (d) Ocean
33. 33.Which of these fits saving in the cloud? (a) the sound on/off setting (b) chat messages to friends (c) a draft you are typing (d) notes to read offline
34. 34.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
35. 35.💾 What number does this code show?
    let points = 6;
    points = points - 2;
    points = points + 4;
    show(points);
36. 36.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Rain", "Monsoon"];
    show(songs[0]); (a) Sunrise (b) Rain (c) Monsoon
37. 37.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 2 (c) 10 (d) 1
38. 38.💾 What number does this code show?
    let points = 5;
    points = points - 5;
    points = points + 5;
    show(points);
39. 39.💾 What number does this code show?
    let notes = ["Sports", "Art"];
    notes.push("Science");
    show(notes.length);
40. 40.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a list (d) a button

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