App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 573 · 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.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
2. 2.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) a shared chat (d) data saved on the phone
3. 3.💾 What number does this code show?
   let friends = ["Kabir", "Arjun", "Meera"];
   friends.push("Aman");
   friends.push("Riya");
   show(friends.length);
4. 4.💾 What does this code show? (Positions start at 0.)
   let notes = ["Maths", "Science", "Sports"];
   show(notes[0]); (a) Sports (b) Maths (c) Science
5. 5.💾 What does this code show? (Positions start at 0.)
   let notes = ["Sports", "Music", "Hindi", "Science"];
   show(notes[1]); (a) Hindi (b) Music (c) Sports (d) Science
6. 6.💾 What does this code show? (Positions start at 0.)
   let notes = ["Maths", "Hindi", "Science", "Sports", "Music"];
   show(notes[2]); (a) Hindi (b) Maths (c) Science (d) Sports
7. 7.💾 pop() takes off the last item. What does this code show?
   let notes = ["Maths", "Art", "Hindi", "Science", "Music"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Hindi (b) Art (c) Science (d) Maths
8. 8.💾 Where should the app save a draft you are typing: 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 songs = ["Ocean", "Stars", "Rain"];
   show(songs[1]); (a) Stars (b) Ocean (c) Rain
10. 10.💾 What does this code show? (Positions start at 0.)
    let friends = ["Zoya", "Riya", "Aman", "Kabir"];
    show(friends[0]); (a) Aman (b) Riya (c) Kabir (d) Zoya
11. 11.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Sunrise", "Stars", "Ocean", "Kites"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Stars (c) Sunrise (d) Rain
12. 12.💾 What number does this code show?
    let notes = ["Maths", "Music", "Art", "Hindi"];
    notes.push("Sports");
    show(notes.length);
13. 13.💾 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
14. 14.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
15. 15.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) your last game level (d) a shared to-do list
16. 16.💾 What number does this code show?
    let notes = ["Art", "Hindi"];
    notes.push("Maths");
    notes.push("Science");
    show(notes.length);
17. 17.💾 What number does this code show?
    let score = 5;
    score = score - 4;
    score = score + 1;
    show(score);
18. 18.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) photos on two devices (d) notes to read offline
19. 19.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) shrink the app (d) never need a password
20. 20.💾 What number does this code show?
    let score = 6;
    score = score - 3;
    score = score + 1;
    show(score);
21. 21.💾 What number does this code show?
    let coins = 7;
    coins = coins - 2;
    coins = coins + 5;
    show(coins);
22. 22.💾 What is a variable? (a) a picture (b) a type of screen (c) a phone setting (d) a named box for a value
23. 23.💾 What number does this code show?
    let songs = ["Ocean", "Kites"];
    songs.push("Rain");
    show(songs.length);
24. 24.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 10 (d) 0
25. 25.Which of these fits saving on the phone? (a) a class leaderboard (b) chat messages to friends (c) a shared to-do list (d) the sound on/off setting
26. 26.💾 Which can hold many values in order? (a) a switch (b) a single number (c) a list (d) a button
27. 27.💾 What does this code show? (Positions start at 0.)
    let songs = ["Stars", "Kites", "Ocean", "Rain"];
    show(songs[3]); (a) Stars (b) Ocean (c) Kites (d) Rain
28. 28.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) the app is closed (c) the phone is lost (d) you send a message
29. 29.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
30. 30.💾 What number does this code show?
    let notes = ["Maths", "Art", "Hindi", "Music"];
    notes.push("Sports");
    show(notes.length);
31. 31.💾 What number does this code show?
    let notes = ["Art", "Maths"];
    notes.push("Science");
    show(notes.length);
32. 32.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) chat messages to friends (d) your last game level
33. 33.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Music", "Sports"];
    show(notes[1]); (a) Music (b) Hindi (c) Sports (d) Art
34. 34.💾 What number does this code show?
    let songs = ["Sunrise", "Monsoon", "Rain"];
    songs.push("Kites");
    songs.push("Stars");
    show(songs.length);
35. 35.💾 What number does this code show?
    let friends = ["Aman", "Meera"];
    friends.push("Zoya");
    friends.push("Kabir");
    show(friends.length);
36. 36.💾 What number does this code show?
    let coins = 3;
    coins = coins - 2;
    coins = coins + 5;
    show(coins);
37. 37.Which of these fits saving on the phone? (a) photos on two devices (b) a class leaderboard (c) chat messages to friends (d) your last game level
38. 38.Which of these fits saving in the cloud? (a) a class leaderboard (b) your last game level (c) the sound on/off setting (d) a draft you are typing
39. 39.True or false: your last game level fits saving on the phone. (a) False (b) True
40. 40.💾 What number does this code show?
    let friends = ["Zoya", "Meera"];
    friends.push("Aman");
    friends.push("Arjun");
    show(friends.length);

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