App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 501 · 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 does this code show? (Positions start at 0.)
   let friends = ["Arjun", "Riya", "Meera", "Zoya"];
   show(friends[0]); (a) Riya (b) Zoya (c) Meera (d) Arjun
2. 2.Which of these fits saving on the phone? (a) photos on two devices (b) notes to read offline (c) chat messages to friends (d) a class leaderboard
3. 3.💾 What does this code show? (Positions start at 0.)
   let songs = ["Stars", "Monsoon", "Kites"];
   show(songs[1]); (a) Kites (b) Monsoon (c) Stars
4. 4.💾 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
5. 5.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
6. 6.💾 What number does this code show?
   let notes = ["Maths", "Music"];
   notes.push("Art");
   show(notes.length);
7. 7.💾 What number does this code show?
   let friends = ["Aman", "Kabir", "Arjun"];
   friends.push("Meera");
   friends.push("Zoya");
   show(friends.length);
8. 8.💾 pop() takes off the last item. What does this code show?
   let songs = ["Monsoon", "Kites", "Ocean", "Rain"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Rain (b) Ocean (c) Kites (d) Monsoon
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.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Science", "Maths"];
    show(notes[1]); (a) Maths (b) Sports (c) Science
11. 11.💾 Which works with no internet at all? (a) a cloud backup (b) data saved on the phone (c) a cloud leaderboard (d) a shared chat
12. 12.💾 What number does this code show?
    let notes = ["Music", "Sports", "Maths"];
    notes.push("Science");
    notes.push("Hindi");
    show(notes.length);
13. 13.💾 What number does this code show?
    let stars = 6;
    stars = stars - 5;
    stars = stars + 3;
    show(stars);
14. 14.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
15. 15.Which of these fits saving in the cloud? (a) your last game level (b) notes to read offline (c) chat messages to friends (d) the sound on/off setting
16. 16.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
17. 17.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
18. 18.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
19. 19.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the phone is lost (c) you send a message (d) the app is closed
20. 20.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
21. 21.💾 What number does this code show?
    let notes = ["Hindi", "Music", "Art"];
    notes.push("Science");
    show(notes.length);
22. 22.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) skip the internet (c) shrink the app (d) never need a password
23. 23.True or false: notes to read offline fits saving on the phone. (a) False (b) True
24. 24.Which of these fits saving in the cloud? (a) a class leaderboard (b) the sound on/off setting (c) a draft you are typing (d) your last game level
25. 25.Which of these fits saving in the cloud? (a) a draft you are typing (b) your last game level (c) the sound on/off setting (d) photos on two devices
26. 26.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Music", "Hindi", "Maths", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Art (c) Maths (d) Hindi
27. 27.True or false: photos on two devices fits saving on the phone. (a) True (b) False
28. 28.💾 What number does this code show?
    let stars = 9;
    stars = stars - 2;
    stars = stars + 1;
    show(stars);
29. 29.💾 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
30. 30.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Kites", "Ocean"];
    show(songs[1]); (a) Ocean (b) Kites (c) Sunrise
31. 31.💾 What is a variable? (a) a type of screen (b) a phone setting (c) a named box for a value (d) a picture
32. 32.💾 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
33. 33.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
34. 34.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 0 (d) 2
35. 35.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
36. 36.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Arjun", "Meera", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Zoya (c) Meera (d) Arjun
37. 37.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Zoya", "Meera", "Arjun", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Meera (c) Zoya (d) Aman
38. 38.💾 What number does this code show?
    let score = 9;
    score = score - 7;
    score = score + 1;
    show(score);
39. 39.💾 Which can hold many values in order? (a) a switch (b) a list (c) a button (d) a single number
40. 40.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Stars", "Kites", "Rain"];
    show(songs[0]); (a) Stars (b) Sunrise (c) Kites (d) Rain

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