App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 782 · 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 number does this code show?
   let points = 4;
   points = points - 3;
   points = points + 4;
   show(points);
2. 2.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) notes to read offline (d) a shared to-do list
3. 3.💾 Where should the app save a draft you are typing: on the phone or in the cloud? (a) on the phone (b) in the cloud
4. 4.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
5. 5.💾 What number does this code show?
   let notes = ["Music", "Art"];
   notes.push("Science");
   show(notes.length);
6. 6.Which of these fits saving on the phone? (a) photos on two devices (b) the sound on/off setting (c) a class leaderboard (d) chat messages to friends
7. 7.True or false: notes to read offline fits saving on the phone. (a) False (b) True
8. 8.💾 What number does this code show?
   let notes = ["Science", "Hindi", "Music", "Maths"];
   notes.push("Art");
   notes.push("Sports");
   show(notes.length);
9. 9.True or false: a class leaderboard fits saving in the cloud. (a) True (b) False
10. 10.💾 Which can hold many values in order? (a) a switch (b) a list (c) a button (d) a single number
11. 11.💾 pop() takes off the last item. What does this code show?
    let friends = ["Kabir", "Arjun", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Arjun (c) Kabir
12. 12.True or false: a shared to-do list fits saving in the cloud. (a) True (b) False
13. 13.Which of these fits saving in the cloud? (a) notes to read offline (b) chat messages to friends (c) the sound on/off setting (d) a draft you are typing
14. 14.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 0 (c) 1 (d) 10
15. 15.💾 What does this code show? (Positions start at 0.)
    let friends = ["Arjun", "Riya", "Zoya", "Kabir"];
    show(friends[3]); (a) Kabir (b) Riya (c) Arjun (d) Zoya
16. 16.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Sports", "Hindi"];
    show(notes[0]); (a) Sports (b) Art (c) Hindi
17. 17.Which of these fits saving on the phone? (a) a class leaderboard (b) a draft you are typing (c) a shared to-do list (d) photos on two devices
18. 18.💾 What number does this code show?
    let notes = ["Maths", "Art", "Sports", "Science"];
    notes.push("Hindi");
    notes.push("Music");
    show(notes.length);
19. 19.💾 What number does this code show?
    let friends = ["Meera", "Arjun"];
    friends.push("Aman");
    show(friends.length);
20. 20.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Meera", "Arjun"];
    show(friends[1]); (a) Riya (b) Aman (c) Arjun (d) Meera
21. 21.True or false: a shared to-do list fits saving on the phone. (a) True (b) False
22. 22.💾 What number does this code show?
    let friends = ["Meera", "Riya"];
    friends.push("Aman");
    friends.push("Kabir");
    show(friends.length);
23. 23.Which of these fits saving in the cloud? (a) a shared to-do list (b) the sound on/off setting (c) your last game level (d) notes to read offline
24. 24.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) on the phone (b) in the cloud
25. 25.💾 What number does this code show?
    let lives = 6;
    lives = lives - 5;
    lives = lives + 2;
    show(lives);
26. 26.💾 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
27. 27.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Aman", "Riya"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Riya (b) Aman (c) Arjun
28. 28.💾 pop() takes off the last item. What does this code show?
    let notes = ["Art", "Music", "Maths", "Science", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Maths (b) Science (c) Music (d) Art
29. 29.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
30. 30.True or false: photos on two devices fits saving on the phone. (a) False (b) True
31. 31.💾 pop() takes off the last item. What does this code show?
    let songs = ["Kites", "Monsoon", "Rain"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Kites (b) Rain (c) Monsoon
32. 32.💾 What number does this code show?
    let coins = 5;
    coins = coins - 3;
    coins = coins + 5;
    show(coins);
33. 33.True or false: photos on two devices fits saving in the cloud. (a) True (b) False
34. 34.💾 What does this code show? (Positions start at 0.)
    let notes = ["Science", "Hindi", "Maths", "Art"];
    show(notes[2]); (a) Art (b) Hindi (c) Maths (d) Science
35. 35.True or false: a draft you are typing fits saving on the phone. (a) True (b) False
36. 36.💾 What does this code show? (Positions start at 0.)
    let friends = ["Meera", "Kabir", "Zoya"];
    show(friends[1]); (a) Zoya (b) Kabir (c) Meera
37. 37.💾 What number does this code show?
    let coins = 9;
    coins = coins - 4;
    coins = coins + 1;
    show(coins);
38. 38.💾 pop() takes off the last item. What does this code show?
    let songs = ["Rain", "Stars", "Ocean"];
    songs.pop();
    show(songs[songs.length - 1]); (a) Ocean (b) Stars (c) Rain
39. 39.💾 What number does this code show?
    let points = 6;
    points = points - 6;
    points = points + 1;
    show(points);
40. 40.💾 Where should the app save notes to read offline: on the phone or in the cloud? (a) in the cloud (b) on the phone

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