App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 584 · 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.💾 pop() takes off the last item. What does this code show?
   let friends = ["Kabir", "Riya", "Meera"];
   friends.pop();
   show(friends[friends.length - 1]); (a) Meera (b) Kabir (c) Riya
2. 2.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) chat messages to friends (d) your last game level
3. 3.True or false: the sound on/off setting fits saving in the cloud. (a) True (b) False
4. 4.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) on the phone (b) in the cloud
5. 5.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
6. 6.True or false: photos on two devices fits saving on the phone. (a) True (b) False
7. 7.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
8. 8.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
9. 9.💾 What does this code show? (Positions start at 0.)
   let notes = ["Science", "Sports", "Art"];
   show(notes[0]); (a) Art (b) Science (c) Sports
10. 10.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a class leaderboard (d) a draft you are typing
11. 11.💾 What number does this code show?
    let score = 7;
    score = score - 7;
    score = score + 3;
    show(score);
12. 12.True or false: your last game level fits saving on the phone. (a) True (b) False
13. 13.💾 What number does this code show?
    let coins = 3;
    coins = coins - 1;
    coins = coins + 5;
    show(coins);
14. 14.💾 What number does this code show?
    let lives = 6;
    lives = lives - 5;
    lives = lives + 2;
    show(lives);
15. 15.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Kabir", "Meera"];
    show(friends[2]); (a) Meera (b) Riya (c) Kabir
16. 16.💾 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
17. 17.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
18. 18.💾 What number does this code show?
    let songs = ["Monsoon", "Kites"];
    songs.push("Stars");
    songs.push("Ocean");
    show(songs.length);
19. 19.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Sunrise", "Kites", "Stars"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Kites (c) Rain (d) Sunrise
20. 20.💾 Saving data in the cloud lets you ___. (a) shrink the app (b) never need a password (c) use it on any device (d) skip the internet
21. 21.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Kabir", "Zoya", "Meera"];
    show(friends[3]); (a) Zoya (b) Kabir (c) Meera (d) Aman
22. 22.💾 What is a variable? (a) a named box for a value (b) a picture (c) a phone setting (d) a type of screen
23. 23.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
24. 24.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 0 (d) 10
25. 25.💾 What number does this code show?
    let notes = ["Hindi", "Sports", "Science"];
    notes.push("Maths");
    show(notes.length);
26. 26.💾 Where should the app save your last game level: on the phone or in the cloud? (a) in the cloud (b) on the phone
27. 27.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) the phone is lost (d) you send a message
28. 28.💾 What number does this code show?
    let stars = 7;
    stars = stars - 4;
    stars = stars + 4;
    show(stars);
29. 29.💾 What number does this code show?
    let friends = ["Zoya", "Meera"];
    friends.push("Arjun");
    friends.push("Riya");
    show(friends.length);
30. 30.💾 What number does this code show?
    let lives = 8;
    lives = lives - 1;
    lives = lives + 3;
    show(lives);
31. 31.💾 What number does this code show?
    let friends = ["Arjun", "Meera"];
    friends.push("Riya");
    friends.push("Zoya");
    show(friends.length);
32. 32.💾 What number does this code show?
    let friends = ["Aman", "Kabir", "Zoya", "Meera"];
    friends.push("Arjun");
    show(friends.length);
33. 33.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Science", "Sports"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Sports (b) Science (c) Hindi
34. 34.Which of these fits saving on the phone? (a) photos on two devices (b) chat messages to friends (c) a draft you are typing (d) a shared to-do list
35. 35.💾 What number does this code show?
    let notes = ["Music", "Art"];
    notes.push("Science");
    notes.push("Maths");
    show(notes.length);
36. 36.True or false: notes to read offline fits saving on the phone. (a) True (b) False
37. 37.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
38. 38.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Music", "Art"];
    show(notes[0]); (a) Art (b) Science (c) Music
39. 39.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
40. 40.Which of these fits saving in the cloud? (a) your last game level (b) a shared to-do list (c) a draft you are typing (d) notes to read offline

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