App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 814 · 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 songs = ["Rain", "Ocean", "Monsoon"];
   songs.push("Kites");
   show(songs.length);
2. 2.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
3. 3.💾 What number does this code show?
   let songs = ["Monsoon", "Rain"];
   songs.push("Sunrise");
   songs.push("Kites");
   show(songs.length);
4. 4.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 10 (c) 2 (d) 0
5. 5.💾 What is a variable? (a) a phone setting (b) a named box for a value (c) a type of screen (d) a picture
6. 6.💾 What number does this code show?
   let songs = ["Rain", "Sunrise", "Monsoon"];
   songs.push("Ocean");
   songs.push("Kites");
   show(songs.length);
7. 7.💾 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
8. 8.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.💾 What does this code show? (Positions start at 0.)
   let notes = ["Music", "Sports", "Science", "Maths", "Art"];
   show(notes[0]); (a) Science (b) Music (c) Sports (d) Maths
10. 10.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
11. 11.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the phone is lost (c) the app is closed (d) the screen turns off
12. 12.💾 What number does this code show?
    let friends = ["Meera", "Riya", "Kabir", "Zoya"];
    friends.push("Aman");
    show(friends.length);
13. 13.💾 What number does this code show?
    let notes = ["Art", "Sports"];
    notes.push("Maths");
    show(notes.length);
14. 14.💾 What number does this code show?
    let score = 9;
    score = score - 5;
    score = score + 1;
    show(score);
15. 15.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Art", "Music", "Science"];
    show(notes[2]); (a) Maths (b) Art (c) Science (d) Music
16. 16.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
17. 17.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
18. 18.💾 Which works with no internet at all? (a) a cloud leaderboard (b) data saved on the phone (c) a cloud backup (d) a shared chat
19. 19.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
20. 20.💾 What number does this code show?
    let friends = ["Zoya", "Riya", "Arjun"];
    friends.push("Kabir");
    friends.push("Aman");
    show(friends.length);
21. 21.💾 What number does this code show?
    let coins = 7;
    coins = coins - 1;
    coins = coins + 1;
    show(coins);
22. 22.💾 What number does this code show?
    let score = 5;
    score = score - 2;
    score = score + 3;
    show(score);
23. 23.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
24. 24.Which of these fits saving in the cloud? (a) your last game level (b) a shared to-do list (c) notes to read offline (d) a draft you are typing
25. 25.💾 Which can hold many values in order? (a) a single number (b) a button (c) a switch (d) a list
26. 26.💾 What number does this code show?
    let points = 6;
    points = points - 6;
    points = points + 2;
    show(points);
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Stars", "Monsoon", "Rain"];
    show(songs[2]); (a) Sunrise (b) Monsoon (c) Rain (d) Stars
28. 28.💾 What number does this code show?
    let friends = ["Aman", "Meera", "Arjun", "Riya"];
    friends.push("Zoya");
    friends.push("Kabir");
    show(friends.length);
29. 29.Which of these fits saving in the cloud? (a) a class leaderboard (b) your last game level (c) the sound on/off setting (d) notes to read offline
30. 30.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Stars", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Kites (c) Stars
31. 31.Which of these fits saving in the cloud? (a) your last game level (b) chat messages to friends (c) notes to read offline (d) the sound on/off setting
32. 32.Which of these fits saving on the phone? (a) chat messages to friends (b) the sound on/off setting (c) a shared to-do list (d) photos on two devices
33. 33.True or false: notes to read offline fits saving on the phone. (a) True (b) False
34. 34.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Music", "Maths", "Hindi", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Hindi (c) Maths (d) Science
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Stars", "Kites", "Monsoon", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Stars (c) Kites (d) Monsoon
36. 36.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Music", "Sports", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Science (c) Sports (d) Hindi
37. 37.True or false: your last game level fits saving on the phone. (a) True (b) False
38. 38.💾 What number does this code show?
    let score = 4;
    score = score - 2;
    score = score + 5;
    show(score);
39. 39.💾 What number does this code show?
    let friends = ["Riya", "Zoya", "Kabir", "Aman"];
    friends.push("Meera");
    friends.push("Arjun");
    show(friends.length);
40. 40.Which of these fits saving on the phone? (a) a draft you are typing (b) a class leaderboard (c) a shared to-do list (d) photos on two devices

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