App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 653 · 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 notes = ["Science", "Hindi", "Sports", "Maths", "Music"];
   show(notes[3]); (a) Science (b) Hindi (c) Sports (d) Maths
2. 2.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) chat messages to friends (d) a draft you are typing
3. 3.💾 What number does this code show?
   let coins = 4;
   coins = coins - 4;
   coins = coins + 2;
   show(coins);
4. 4.💾 What number does this code show?
   let songs = ["Sunrise", "Rain", "Kites"];
   songs.push("Ocean");
   show(songs.length);
5. 5.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud leaderboard (c) a cloud backup (d) a shared chat
6. 6.💾 What number does this code show?
   let coins = 9;
   coins = coins - 5;
   coins = coins + 5;
   show(coins);
7. 7.💾 What number does this code show?
   let songs = ["Sunrise", "Monsoon", "Ocean", "Rain"];
   songs.push("Stars");
   songs.push("Kites");
   show(songs.length);
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.💾 What does this code show? (Positions start at 0.)
   let songs = ["Kites", "Sunrise", "Rain", "Monsoon"];
   show(songs[1]); (a) Monsoon (b) Kites (c) Sunrise (d) Rain
10. 10.💾 What number does this code show?
    let points = 9;
    points = points - 7;
    points = points + 1;
    show(points);
11. 11.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a button (d) a list
12. 12.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
13. 13.💾 What number does this code show?
    let stars = 4;
    stars = stars - 2;
    stars = stars + 1;
    show(stars);
14. 14.💾 What number does this code show?
    let songs = ["Ocean", "Rain", "Kites", "Sunrise"];
    songs.push("Stars");
    songs.push("Monsoon");
    show(songs.length);
15. 15.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
16. 16.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
17. 17.💾 What number does this code show?
    let lives = 8;
    lives = lives - 4;
    lives = lives + 1;
    show(lives);
18. 18.💾 What number does this code show?
    let stars = 9;
    stars = stars - 9;
    stars = stars + 3;
    show(stars);
19. 19.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
20. 20.💾 What number does this code show?
    let stars = 8;
    stars = stars - 2;
    stars = stars + 3;
    show(stars);
21. 21.Which of these fits saving in the cloud? (a) notes to read offline (b) the sound on/off setting (c) your last game level (d) a shared to-do list
22. 22.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
23. 23.💾 What number does this code show?
    let songs = ["Monsoon", "Sunrise", "Kites"];
    songs.push("Ocean");
    show(songs.length);
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.True or false: your last game level fits saving on the phone. (a) False (b) True
26. 26.💾 In most code, the first item of a list is at position ___. (a) 0 (b) 1 (c) 2 (d) 10
27. 27.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Art", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Maths (c) Sports
28. 28.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
29. 29.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) photos on two devices (d) notes to read offline
30. 30.💾 What is a variable? (a) a picture (b) a phone setting (c) a type of screen (d) a named box for a value
31. 31.💾 What number does this code show?
    let friends = ["Aman", "Meera", "Kabir"];
    friends.push("Zoya");
    show(friends.length);
32. 32.💾 What number does this code show?
    let songs = ["Kites", "Sunrise", "Monsoon"];
    songs.push("Ocean");
    show(songs.length);
33. 33.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Art", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Hindi
34. 34.💾 What number does this code show?
    let friends = ["Kabir", "Meera", "Aman", "Riya"];
    friends.push("Arjun");
    show(friends.length);
35. 35.💾 What number does this code show?
    let notes = ["Sports", "Hindi"];
    notes.push("Art");
    notes.push("Music");
    show(notes.length);
36. 36.True or false: notes to read offline fits saving on the phone. (a) False (b) True
37. 37.Which of these fits saving in the cloud? (a) photos on two devices (b) the sound on/off setting (c) your last game level (d) a draft you are typing
38. 38.💾 What number does this code show?
    let friends = ["Meera", "Riya", "Kabir", "Zoya"];
    friends.push("Arjun");
    friends.push("Aman");
    show(friends.length);
39. 39.💾 What number does this code show?
    let songs = ["Monsoon", "Rain", "Kites", "Stars"];
    songs.push("Sunrise");
    songs.push("Ocean");
    show(songs.length);
40. 40.💾 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

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