App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 251 · 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.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
2. 2.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) in the cloud (b) on the phone
3. 3.💾 What number does this code show?
   let coins = 5;
   coins = coins - 5;
   coins = coins + 2;
   show(coins);
4. 4.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 1 (c) 2 (d) 0
5. 5.True or false: a draft you are typing fits saving on the phone. (a) False (b) True
6. 6.💾 What does this code show? (Positions start at 0.)
   let notes = ["Hindi", "Sports", "Maths"];
   show(notes[2]); (a) Hindi (b) Sports (c) Maths
7. 7.💾 What is a variable? (a) a named box for a value (b) a picture (c) a phone setting (d) a type of screen
8. 8.Which of these fits saving on the phone? (a) a shared to-do list (b) a class leaderboard (c) photos on two devices (d) a draft you are typing
9. 9.True or false: the sound on/off setting fits saving in the cloud. (a) False (b) True
10. 10.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Meera", "Arjun", "Zoya", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Zoya (c) Arjun (d) Aman
11. 11.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) in the cloud (b) on the phone
12. 12.💾 Which works with no internet at all? (a) data saved on the phone (b) a cloud backup (c) a shared chat (d) a cloud leaderboard
13. 13.Which of these fits saving on the phone? (a) a class leaderboard (b) your last game level (c) photos on two devices (d) chat messages to friends
14. 14.Which of these fits saving in the cloud? (a) the sound on/off setting (b) photos on two devices (c) your last game level (d) notes to read offline
15. 15.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Zoya", "Kabir", "Riya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Kabir (c) Zoya (d) Arjun
16. 16.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) in the cloud (b) on the phone
17. 17.True or false: notes to read offline fits saving in the cloud. (a) True (b) False
18. 18.💾 What number does this code show?
    let songs = ["Kites", "Rain", "Monsoon", "Sunrise"];
    songs.push("Ocean");
    songs.push("Stars");
    show(songs.length);
19. 19.💾 What does this code show? (Positions start at 0.)
    let notes = ["Music", "Science", "Hindi", "Sports", "Maths"];
    show(notes[4]); (a) Hindi (b) Maths (c) Music (d) Science
20. 20.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
21. 21.💾 What number does this code show?
    let score = 4;
    score = score - 4;
    score = score + 3;
    show(score);
22. 22.💾 Data saved only on the phone is lost when ___. (a) the app is closed (b) the screen turns off (c) you send a message (d) the phone is lost
23. 23.💾 What number does this code show?
    let coins = 4;
    coins = coins - 3;
    coins = coins + 1;
    show(coins);
24. 24.💾 What number does this code show?
    let points = 4;
    points = points - 3;
    points = points + 2;
    show(points);
25. 25.💾 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
26. 26.Which of these fits saving in the cloud? (a) a class leaderboard (b) the sound on/off setting (c) your last game level (d) a draft you are typing
27. 27.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Arjun", "Meera", "Riya"];
    show(friends[2]); (a) Arjun (b) Aman (c) Riya (d) Meera
28. 28.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
29. 29.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Science", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Hindi (c) Science
30. 30.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Kites", "Ocean", "Rain"];
    show(songs[0]); (a) Kites (b) Ocean (c) Monsoon (d) Rain
31. 31.💾 What number does this code show?
    let score = 4;
    score = score - 3;
    score = score + 1;
    show(score);
32. 32.💾 What number does this code show?
    let friends = ["Meera", "Zoya"];
    friends.push("Kabir");
    friends.push("Riya");
    show(friends.length);
33. 33.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
34. 34.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Maths", "Art", "Science"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Art (b) Maths (c) Science (d) Music
35. 35.True or false: your last game level fits saving in the cloud. (a) True (b) False
36. 36.💾 What number does this code show?
    let friends = ["Aman", "Meera"];
    friends.push("Riya");
    show(friends.length);
37. 37.Which of these fits saving on the phone? (a) a class leaderboard (b) photos on two devices (c) chat messages to friends (d) notes to read offline
38. 38.💾 What number does this code show?
    let coins = 5;
    coins = coins - 5;
    coins = coins + 1;
    show(coins);
39. 39.💾 What number does this code show?
    let coins = 8;
    coins = coins - 4;
    coins = coins + 3;
    show(coins);
40. 40.💾 What number does this code show?
    let friends = ["Kabir", "Riya"];
    friends.push("Zoya");
    friends.push("Aman");
    show(friends.length);

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