App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 918 · 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.💾 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
2. 2.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
3. 3.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
4. 4.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) never need a password (d) shrink the app
5. 5.💾 What number does this code show?
   let friends = ["Meera", "Riya", "Aman", "Arjun"];
   friends.push("Zoya");
   show(friends.length);
6. 6.💾 pop() takes off the last item. What does this code show?
   let songs = ["Stars", "Sunrise", "Rain"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Stars (b) Sunrise (c) Rain
7. 7.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 10 (d) 2
8. 8.💾 pop() takes off the last item. What does this code show?
   let friends = ["Meera", "Aman", "Kabir", "Arjun"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Meera (b) Aman (c) Arjun (d) Kabir
9. 9.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
10. 10.💾 What number does this code show?
    let points = 7;
    points = points - 1;
    points = points + 3;
    show(points);
11. 11.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Hindi", "Art", "Music", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Music (d) Maths
12. 12.Which of these fits saving in the cloud? (a) notes to read offline (b) a draft you are typing (c) the sound on/off setting (d) chat messages to friends
13. 13.Which of these fits saving in the cloud? (a) photos on two devices (b) your last game level (c) a draft you are typing (d) the sound on/off setting
14. 14.💾 What number does this code show?
    let lives = 9;
    lives = lives - 3;
    lives = lives + 2;
    show(lives);
15. 15.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a cloud backup (c) a shared chat (d) data saved on the phone
16. 16.💾 Data saved only on the phone is lost when ___. (a) you send a message (b) the screen turns off (c) the app is closed (d) the phone is lost
17. 17.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Art", "Hindi", "Music"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Hindi (c) Art (d) Music
18. 18.💾 What number does this code show?
    let songs = ["Monsoon", "Stars", "Rain", "Sunrise"];
    songs.push("Kites");
    songs.push("Ocean");
    show(songs.length);
19. 19.💾 What number does this code show?
    let score = 6;
    score = score - 6;
    score = score + 2;
    show(score);
20. 20.💾 What number does this code show?
    let points = 5;
    points = points - 1;
    points = points + 4;
    show(points);
21. 21.Which of these fits saving on the phone? (a) chat messages to friends (b) a shared to-do list (c) your last game level (d) photos on two devices
22. 22.💾 What number does this code show?
    let songs = ["Kites", "Rain", "Sunrise"];
    songs.push("Ocean");
    show(songs.length);
23. 23.True or false: a class leaderboard fits saving on the phone. (a) True (b) False
24. 24.💾 Which can hold many values in order? (a) a single number (b) a button (c) a switch (d) a list
25. 25.💾 pop() takes off the last item. What does this code show?
    let songs = ["Sunrise", "Ocean", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Monsoon (c) Sunrise
26. 26.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
27. 27.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Arjun", "Riya"];
    show(friends[0]); (a) Arjun (b) Meera (c) Riya
28. 28.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.💾 What is a variable? (a) a phone setting (b) a type of screen (c) a picture (d) a named box for a value
30. 30.True or false: your last game level fits saving on the phone. (a) True (b) False
31. 31.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) a class leaderboard (d) notes to read offline
32. 32.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Kabir", "Meera", "Riya"];
    show(friends[0]); (a) Kabir (b) Riya (c) Aman (d) Meera
33. 33.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
34. 34.💾 What number does this code show?
    let coins = 6;
    coins = coins - 4;
    coins = coins + 4;
    show(coins);
35. 35.💾 What number does this code show?
    let score = 5;
    score = score - 1;
    score = score + 3;
    show(score);
36. 36.💾 What number does this code show?
    let score = 3;
    score = score - 2;
    score = score + 1;
    show(score);
37. 37.True or false: notes to read offline fits saving on the phone. (a) False (b) True
38. 38.💾 What number does this code show?
    let songs = ["Ocean", "Kites"];
    songs.push("Stars");
    show(songs.length);
39. 39.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Riya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Riya (c) Aman
40. 40.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Aman", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Aman (c) Arjun

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