App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 561 · 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 notes = ["Science", "Hindi"];
   notes.push("Art");
   show(notes.length);
2. 2.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) chat messages to friends (d) notes to read offline
3. 3.💾 What number does this code show?
   let score = 4;
   score = score - 2;
   score = score + 5;
   show(score);
4. 4.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) chat messages to friends (d) the sound on/off setting
5. 5.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
6. 6.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
7. 7.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
8. 8.💾 Data saved only on the phone is lost when ___. (a) the screen turns off (b) you send a message (c) the app is closed (d) the phone is lost
9. 9.💾 What number does this code show?
   let score = 5;
   score = score - 3;
   score = score + 4;
   show(score);
10. 10.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Sunrise"];
    show(songs[0]); (a) Rain (b) Monsoon (c) Sunrise
11. 11.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 2 (d) 0
12. 12.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Stars", "Monsoon"];
    show(songs[0]); (a) Sunrise (b) Stars (c) Monsoon
13. 13.💾 What number does this code show?
    let songs = ["Stars", "Monsoon", "Rain", "Ocean"];
    songs.push("Kites");
    show(songs.length);
14. 14.💾 Which can hold many values in order? (a) a list (b) a button (c) a switch (d) a single number
15. 15.True or false: notes to read offline fits saving on the phone. (a) True (b) False
16. 16.💾 What is a variable? (a) a named box for a value (b) a picture (c) a type of screen (d) a phone setting
17. 17.💾 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
18. 18.💾 What number does this code show?
    let points = 5;
    points = points - 2;
    points = points + 2;
    show(points);
19. 19.💾 What number does this code show?
    let notes = ["Art", "Hindi"];
    notes.push("Sports");
    show(notes.length);
20. 20.💾 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
21. 21.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Music", "Sports", "Science", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Science (c) Sports (d) Music
22. 22.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Kabir", "Aman", "Zoya", "Meera"];
    show(friends[1]); (a) Kabir (b) Zoya (c) Aman (d) Riya
23. 23.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
24. 24.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
25. 25.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
26. 26.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
27. 27.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Stars", "Sunrise", "Monsoon", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Stars (b) Sunrise (c) Monsoon (d) Ocean
28. 28.True or false: photos on two devices fits saving on the phone. (a) True (b) False
29. 29.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Aman", "Kabir", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Arjun (c) Kabir (d) Aman
30. 30.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud leaderboard (c) a shared chat (d) a cloud backup
31. 31.💾 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
32. 32.💾 What number does this code show?
    let notes = ["Hindi", "Maths", "Science"];
    notes.push("Sports");
    notes.push("Art");
    show(notes.length);
33. 33.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Rain", "Stars", "Ocean", "Sunrise"];
    show(songs[1]); (a) Ocean (b) Stars (c) Rain (d) Monsoon
34. 34.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) photos on two devices (d) your last game level
35. 35.💾 What number does this code show?
    let songs = ["Monsoon", "Rain"];
    songs.push("Sunrise");
    show(songs.length);
36. 36.💾 What number does this code show?
    let stars = 4;
    stars = stars - 3;
    stars = stars + 3;
    show(stars);
37. 37.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Maths", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Maths (c) Sports
38. 38.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Science", "Maths", "Hindi"];
    show(notes[3]); (a) Maths (b) Science (c) Art (d) Hindi
39. 39.💾 What number does this code show?
    let lives = 5;
    lives = lives - 5;
    lives = lives + 1;
    show(lives);
40. 40.💾 What number does this code show?
    let points = 6;
    points = points - 1;
    points = points + 3;
    show(points);

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