App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 697 · 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 = ["Arjun", "Zoya", "Riya"];
   show(friends[2]); (a) Arjun (b) Zoya (c) Riya
2. 2.💾 Which can hold many values in order? (a) a button (b) a switch (c) a list (d) a single number
3. 3.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
4. 4.💾 pop() takes off the last item. What does this code show?
   let notes = ["Hindi", "Maths", "Sports"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Hindi (b) Sports (c) Maths
5. 5.💾 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
6. 6.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) a shared to-do list (d) your last game level
7. 7.Which of these fits saving on the phone? (a) chat messages to friends (b) your last game level (c) photos on two devices (d) a class leaderboard
8. 8.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) in the cloud (b) on the phone
9. 9.💾 What number does this code show?
   let coins = 9;
   coins = coins - 2;
   coins = coins + 1;
   show(coins);
10. 10.True or false: your last game level fits saving on the phone. (a) False (b) True
11. 11.💾 What number does this code show?
    let score = 7;
    score = score - 4;
    score = score + 2;
    show(score);
12. 12.💾 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
13. 13.Which of these fits saving on the phone? (a) chat messages to friends (b) the sound on/off setting (c) photos on two devices (d) a shared to-do list
14. 14.💾 What number does this code show?
    let coins = 8;
    coins = coins - 7;
    coins = coins + 1;
    show(coins);
15. 15.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
16. 16.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
17. 17.💾 What number does this code show?
    let songs = ["Rain", "Stars"];
    songs.push("Monsoon");
    songs.push("Ocean");
    show(songs.length);
18. 18.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Sports", "Hindi", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Music (b) Hindi (c) Sports (d) Maths
19. 19.💾 Data saved only on the phone is lost when ___. (a) the phone is lost (b) the screen turns off (c) you send a message (d) the app is closed
20. 20.💾 In most code, the first item of a list is at position ___. (a) 10 (b) 2 (c) 0 (d) 1
21. 21.True or false: photos on two devices fits saving on the phone. (a) False (b) True
22. 22.True or false: a draft you are typing fits saving in the cloud. (a) True (b) False
23. 23.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) use it on any device (c) never need a password (d) shrink the app
24. 24.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Riya", "Arjun", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Arjun (b) Aman (c) Riya (d) Zoya
25. 25.💾 pop() takes off the last item. What does this code show?
    let notes = ["Music", "Art", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Art (c) Music
26. 26.💾 What is a variable? (a) a named box for a value (b) a type of screen (c) a phone setting (d) a picture
27. 27.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Zoya", "Riya", "Aman"];
    show(friends[1]); (a) Zoya (b) Arjun (c) Aman (d) Riya
28. 28.Which of these fits saving in the cloud? (a) a class leaderboard (b) the sound on/off setting (c) a draft you are typing (d) notes to read offline
29. 29.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Riya", "Zoya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Zoya (c) Riya (d) Aman
30. 30.💾 What number does this code show?
    let score = 4;
    score = score - 3;
    score = score + 2;
    show(score);
31. 31.💾 What number does this code show?
    let friends = ["Aman", "Meera"];
    friends.push("Zoya");
    show(friends.length);
32. 32.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
33. 33.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
34. 34.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) chat messages to friends (d) a draft you are typing
35. 35.💾 What number does this code show?
    let notes = ["Sports", "Art"];
    notes.push("Music");
    notes.push("Maths");
    show(notes.length);
36. 36.💾 pop() takes off the last item. What does this code show?
    let friends = ["Meera", "Riya", "Kabir", "Arjun", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Meera (b) Riya (c) Arjun (d) Kabir
37. 37.💾 Which works with no internet at all? (a) a shared chat (b) a cloud leaderboard (c) a cloud backup (d) data saved on the phone
38. 38.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
39. 39.💾 What number does this code show?
    let notes = ["Music", "Art"];
    notes.push("Maths");
    notes.push("Sports");
    show(notes.length);
40. 40.💾 What number does this code show?
    let points = 3;
    points = points - 1;
    points = points + 3;
    show(points);

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