App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 957 · 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.💾 What does this code show? (Positions start at 0.)
   let songs = ["Sunrise", "Rain", "Monsoon"];
   show(songs[2]); (a) Sunrise (b) Rain (c) Monsoon
3. 3.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 0 (c) 2 (d) 10
4. 4.💾 What number does this code show?
   let friends = ["Kabir", "Zoya", "Riya", "Meera"];
   friends.push("Aman");
   friends.push("Arjun");
   show(friends.length);
5. 5.Which of these fits saving on the phone? (a) photos on two devices (b) a draft you are typing (c) chat messages to friends (d) a class leaderboard
6. 6.💾 What number does this code show?
   let songs = ["Kites", "Sunrise"];
   songs.push("Stars");
   songs.push("Rain");
   show(songs.length);
7. 7.💾 pop() takes off the last item. What does this code show?
   let notes = ["Sports", "Art", "Science", "Hindi"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Science (b) Sports (c) Art (d) Hindi
8. 8.💾 What number does this code show?
   let stars = 5;
   stars = stars - 4;
   stars = stars + 3;
   show(stars);
9. 9.💾 What number does this code show?
   let stars = 8;
   stars = stars - 1;
   stars = stars + 3;
   show(stars);
10. 10.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
11. 11.💾 What does this code show? (Positions start at 0.)
    let songs = ["Sunrise", "Ocean", "Monsoon", "Kites", "Rain"];
    show(songs[1]); (a) Monsoon (b) Sunrise (c) Ocean (d) Kites
12. 12.💾 What does this code show? (Positions start at 0.)
    let notes = ["Sports", "Science", "Maths"];
    show(notes[2]); (a) Maths (b) Sports (c) Science
13. 13.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
14. 14.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
15. 15.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
16. 16.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
17. 17.💾 What number does this code show?
    let points = 3;
    points = points - 1;
    points = points + 4;
    show(points);
18. 18.True or false: chat messages to friends fits saving in the cloud. (a) True (b) False
19. 19.💾 What number does this code show?
    let stars = 8;
    stars = stars - 4;
    stars = stars + 2;
    show(stars);
20. 20.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Hindi", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Hindi (b) Sports (c) Art
21. 21.💾 What number does this code show?
    let friends = ["Aman", "Arjun"];
    friends.push("Meera");
    friends.push("Zoya");
    show(friends.length);
22. 22.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
23. 23.Which of these fits saving on the phone? (a) your last game level (b) chat messages to friends (c) a class leaderboard (d) a shared to-do list
24. 24.💾 What number does this code show?
    let notes = ["Hindi", "Maths", "Music"];
    notes.push("Sports");
    notes.push("Science");
    show(notes.length);
25. 25.💾 What number does this code show?
    let notes = ["Hindi", "Music"];
    notes.push("Science");
    notes.push("Sports");
    show(notes.length);
26. 26.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Riya", "Kabir", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Riya (c) Arjun (d) Kabir
27. 27.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
28. 28.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Arjun", "Meera", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Zoya (c) Arjun (d) Riya
29. 29.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) photos on two devices (d) your last game level
30. 30.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) notes to read offline (d) a shared to-do list
31. 31.💾 pop() takes off the last item. What does this code show?
    let notes = ["Sports", "Science", "Hindi", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Sports (c) Science (d) Hindi
32. 32.💾 Which works with no internet at all? (a) a cloud leaderboard (b) a shared chat (c) data saved on the phone (d) a cloud backup
33. 33.💾 What number does this code show?
    let notes = ["Science", "Sports"];
    notes.push("Art");
    show(notes.length);
34. 34.💾 What is a variable? (a) a type of screen (b) a picture (c) a phone setting (d) a named box for a value
35. 35.💾 pop() takes off the last item. What does this code show?
    let songs = ["Ocean", "Rain", "Monsoon"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Monsoon (b) Ocean (c) Rain
36. 36.💾 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
37. 37.💾 Which can hold many values in order? (a) a button (b) a switch (c) a list (d) a single number
38. 38.💾 What number does this code show?
    let notes = ["Maths", "Art", "Hindi", "Sports"];
    notes.push("Music");
    show(notes.length);
39. 39.💾 Saving data in the cloud lets you ___. (a) use it on any device (b) shrink the app (c) never need a password (d) skip the internet
40. 40.True or false: notes to read offline fits saving on the phone. (a) True (b) False

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