App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 790 · 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 songs = ["Sunrise", "Stars", "Kites"];
   show(songs[1]); (a) Sunrise (b) Stars (c) Kites
2. 2.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone
3. 3.💾 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
4. 4.Which of these fits saving on the phone? (a) a shared to-do list (b) photos on two devices (c) chat messages to friends (d) a draft you are typing
5. 5.True or false: notes to read offline fits saving on the phone. (a) True (b) False
6. 6.💾 What does this code show? (Positions start at 0.)
   let songs = ["Rain", "Monsoon", "Kites"];
   show(songs[0]); (a) Monsoon (b) Rain (c) Kites
7. 7.💾 What is a variable? (a) a phone setting (b) a picture (c) a type of screen (d) a named box for a value
8. 8.True or false: your last game level fits saving in the cloud. (a) False (b) True
9. 9.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
10. 10.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
11. 11.Which of these fits saving on the phone? (a) a class leaderboard (b) a shared to-do list (c) the sound on/off setting (d) chat messages to friends
12. 12.💾 What number does this code show?
    let friends = ["Riya", "Arjun", "Kabir"];
    friends.push("Zoya");
    friends.push("Aman");
    show(friends.length);
13. 13.True or false: photos on two devices fits saving on the phone. (a) True (b) False
14. 14.True or false: the sound on/off setting fits saving on the phone. (a) False (b) True
15. 15.True or false: chat messages to friends fits saving on the phone. (a) False (b) True
16. 16.Which of these fits saving on the phone? (a) your last game level (b) photos on two devices (c) chat messages to friends (d) a shared to-do list
17. 17.True or false: chat messages to friends fits saving in the cloud. (a) False (b) True
18. 18.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a class leaderboard (d) your last game level
19. 19.💾 What number does this code show?
    let coins = 8;
    coins = coins - 2;
    coins = coins + 2;
    show(coins);
20. 20.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Monsoon", "Kites", "Stars", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Rain (b) Monsoon (c) Stars (d) Kites
21. 21.💾 What number does this code show?
    let songs = ["Ocean", "Monsoon"];
    songs.push("Sunrise");
    songs.push("Rain");
    show(songs.length);
22. 22.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Meera", "Kabir", "Zoya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Zoya (c) Kabir (d) Meera
23. 23.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
24. 24.💾 In most code, the first item of a list is at position ___. (a) 1 (b) 2 (c) 0 (d) 10
25. 25.💾 What does this code show? (Positions start at 0.)
    let notes = ["Maths", "Music", "Hindi", "Art"];
    show(notes[3]); (a) Hindi (b) Art (c) Music (d) Maths
26. 26.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Kabir", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Kabir (b) Aman (c) Zoya
27. 27.💾 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
28. 28.💾 What number does this code show?
    let friends = ["Zoya", "Riya", "Arjun"];
    friends.push("Aman");
    friends.push("Kabir");
    show(friends.length);
29. 29.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Riya", "Aman", "Kabir", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Aman (b) Kabir (c) Riya (d) Arjun
30. 30.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
31. 31.💾 What does this code show? (Positions start at 0.)
    let friends = ["Kabir", "Riya", "Zoya", "Aman"];
    show(friends[3]); (a) Aman (b) Riya (c) Zoya (d) Kabir
32. 32.💾 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
33. 33.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) never need a password (c) shrink the app (d) use it on any device
34. 34.Which of these fits saving in the cloud? (a) the sound on/off setting (b) notes to read offline (c) a shared to-do list (d) your last game level
35. 35.💾 Which can hold many values in order? (a) a button (b) a switch (c) a list (d) a single number
36. 36.True or false: your last game level fits saving on the phone. (a) False (b) True
37. 37.💾 What number does this code show?
    let notes = ["Maths", "Sports", "Hindi", "Music"];
    notes.push("Art");
    show(notes.length);
38. 38.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
39. 39.Which of these fits saving in the cloud? (a) your last game level (b) the sound on/off setting (c) notes to read offline (d) chat messages to friends
40. 40.💾 What number does this code show?
    let friends = ["Arjun", "Meera"];
    friends.push("Zoya");
    show(friends.length);

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