App Dev Worksheet: Variables, Lists and Saving

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

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