App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 904 · 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) True (b) False
2. 2.💾 pop() takes off the last item. What does this code show?
   let notes = ["Art", "Sports", "Hindi", "Science"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Science (c) Hindi (d) Art
3. 3.💾 What does this code show? (Positions start at 0.)
   let notes = ["Art", "Maths", "Science"];
   show(notes[1]); (a) Art (b) Maths (c) Science
4. 4.💾 What is a variable? (a) a phone setting (b) a picture (c) a named box for a value (d) a type of screen
5. 5.💾 pop() takes off the last item. What does this code show?
   let notes = ["Sports", "Music", "Science", "Hindi"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Sports (b) Science (c) Music (d) Hindi
6. 6.💾 What does this code show? (Positions start at 0.)
   let friends = ["Kabir", "Aman", "Meera", "Riya"];
   show(friends[2]); (a) Aman (b) Meera (c) Riya (d) Kabir
7. 7.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the screen turns off (c) you send a message (d) the app is closed
8. 8.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
9. 9.💾 pop() takes off the last item. What does this code show?
   let songs = ["Stars", "Rain", "Sunrise", "Kites", "Ocean"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Stars (d) Sunrise
10. 10.💾 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
11. 11.💾 Which can hold many values in order? (a) a single number (b) a button (c) a switch (d) a list
12. 12.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
13. 13.True or false: your last game level fits saving in the cloud. (a) False (b) True
14. 14.True or false: photos on two devices fits saving on the phone. (a) False (b) True
15. 15.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
16. 16.💾 What number does this code show?
    let lives = 5;
    lives = lives - 4;
    lives = lives + 3;
    show(lives);
17. 17.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
18. 18.Which of these fits saving on the phone? (a) photos on two devices (b) your last game level (c) chat messages to friends (d) a class leaderboard
19. 19.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 0 (c) 2 (d) 1
20. 20.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
21. 21.True or false: a shared to-do list fits saving on the phone. (a) False (b) True
22. 22.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
23. 23.Which of these fits saving on the phone? (a) a draft you are typing (b) a shared to-do list (c) photos on two devices (d) chat messages to friends
24. 24.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
25. 25.💾 What number does this code show?
    let songs = ["Sunrise", "Ocean"];
    songs.push("Kites");
    songs.push("Monsoon");
    show(songs.length);
26. 26.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Hindi", "Science", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Music (c) Science (d) Hindi
27. 27.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Arjun", "Kabir"];
    show(friends[2]); (a) Riya (b) Arjun (c) Kabir
28. 28.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Sunrise", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Sunrise (c) Kites
29. 29.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Ocean", "Rain", "Monsoon", "Stars"];
    show(songs[1]); (a) Monsoon (b) Sunrise (c) Ocean (d) Rain
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Music", "Science", "Sports"];
    show(notes[4]); (a) Music (b) Maths (c) Art (d) Sports
31. 31.💾 What number does this code show?
    let notes = ["Art", "Maths", "Science"];
    notes.push("Music");
    notes.push("Hindi");
    show(notes.length);
32. 32.💾 What number does this code show?
    let notes = ["Music", "Sports", "Art", "Maths"];
    notes.push("Hindi");
    notes.push("Science");
    show(notes.length);
33. 33.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
34. 34.💾 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
35. 35.💾 What number does this code show?
    let stars = 8;
    stars = stars - 2;
    stars = stars + 5;
    show(stars);
36. 36.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
37. 37.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Arjun", "Meera", "Riya"];
    show(friends[3]); (a) Meera (b) Zoya (c) Arjun (d) Riya
38. 38.Which of these fits saving in the cloud? (a) the sound on/off setting (b) your last game level (c) a draft you are typing (d) a shared to-do list
39. 39.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Zoya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Zoya (c) Aman
40. 40.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) notes to read offline (d) chat messages to friends

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