App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 947 · 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 score = 3;
   score = score - 2;
   score = score + 3;
   show(score);
2. 2.💾 Which works with no internet at all? (a) data saved on the phone (b) a shared chat (c) a cloud backup (d) a cloud leaderboard
3. 3.💾 What does this code show? (Positions start at 0.)
   let notes = ["Science", "Sports", "Art"];
   show(notes[2]); (a) Science (b) Art (c) Sports
4. 4.💾 pop() takes off the last item. What does this code show?
   let songs = ["Stars", "Rain", "Monsoon", "Ocean"];
   songs.pop();
   show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Monsoon (d) Stars
5. 5.💾 Saving data in the cloud lets you ___. (a) never need a password (b) shrink the app (c) skip the internet (d) use it on any device
6. 6.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
7. 7.True or false: your last game level fits saving on the phone. (a) False (b) True
8. 8.💾 What number does this code show?
   let lives = 4;
   lives = lives - 4;
   lives = lives + 2;
   show(lives);
9. 9.💾 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
10. 10.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Arjun", "Zoya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Meera (c) Aman (d) Zoya
11. 11.Which of these fits saving in the cloud? (a) photos on two devices (b) notes to read offline (c) the sound on/off setting (d) a draft you are typing
12. 12.Which of these fits saving in the cloud? (a) the sound on/off setting (b) chat messages to friends (c) a draft you are typing (d) notes to read offline
13. 13.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Ocean", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Rain (c) Kites (d) Sunrise
14. 14.💾 What number does this code show?
    let lives = 6;
    lives = lives - 6;
    lives = lives + 5;
    show(lives);
15. 15.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
16. 16.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
17. 17.💾 Which can hold many values in order? (a) a single number (b) a switch (c) a button (d) a list
18. 18.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Music", "Sports", "Hindi", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Maths (c) Music (d) Sports
19. 19.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Aman", "Riya", "Meera"];
    show(friends[1]); (a) Meera (b) Aman (c) Zoya (d) Riya
20. 20.Which of these fits saving on the phone? (a) a shared to-do list (b) the sound on/off setting (c) chat messages to friends (d) a class leaderboard
21. 21.Which of these fits saving on the phone? (a) photos on two devices (b) a shared to-do list (c) a class leaderboard (d) notes to read offline
22. 22.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
23. 23.💾 What number does this code show?
    let songs = ["Ocean", "Stars"];
    songs.push("Kites");
    songs.push("Monsoon");
    show(songs.length);
24. 24.💾 What number does this code show?
    let score = 4;
    score = score - 1;
    score = score + 2;
    show(score);
25. 25.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Sunrise", "Monsoon", "Stars", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Stars (c) Kites (d) Sunrise
26. 26.💾 What number does this code show?
    let songs = ["Ocean", "Stars", "Kites"];
    songs.push("Sunrise");
    show(songs.length);
27. 27.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 2 (d) 10
28. 28.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Aman", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Meera (c) Aman
29. 29.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Rain", "Monsoon", "Kites", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Monsoon (d) Stars
30. 30.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Music", "Art", "Hindi", "Sports"];
    show(notes[3]); (a) Art (b) Science (c) Hindi (d) Music
31. 31.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
32. 32.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Maths", "Music", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Music (c) Maths (d) Art
33. 33.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
34. 34.Which of these fits saving on the phone? (a) chat messages to friends (b) photos on two devices (c) your last game level (d) a class leaderboard
35. 35.💾 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
36. 36.💾 What number does this code show?
    let songs = ["Rain", "Sunrise"];
    songs.push("Kites");
    songs.push("Stars");
    show(songs.length);
37. 37.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
38. 38.💾 What number does this code show?
    let friends = ["Riya", "Meera"];
    friends.push("Aman");
    friends.push("Arjun");
    show(friends.length);
39. 39.💾 What number does this code show?
    let lives = 7;
    lives = lives - 3;
    lives = lives + 1;
    show(lives);
40. 40.True or false: your last game level fits saving in the cloud. (a) True (b) False

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