App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 150 · 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.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
2. 2.True or false: a draft you are typing fits saving in the cloud. (a) False (b) True
3. 3.True or false: notes to read offline fits saving in the cloud. (a) False (b) True
4. 4.True or false: your last game level fits saving in the cloud. (a) False (b) True
5. 5.💾 Saving data in the cloud lets you ___. (a) never need a password (b) skip the internet (c) shrink the app (d) use it on any device
6. 6.💾 What number does this code show?
   let notes = ["Art", "Hindi", "Science", "Sports"];
   notes.push("Maths");
   show(notes.length);
7. 7.Which of these fits saving on the phone? (a) a draft you are typing (b) chat messages to friends (c) a class leaderboard (d) photos on two devices
8. 8.💾 pop() takes off the last item. What does this code show?
   let notes = ["Art", "Sports", "Maths", "Science"];
   notes.pop();
   show(notes[notes.length - 1]); (a) Science (b) Art (c) Maths (d) Sports
9. 9.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
10. 10.💾 What number does this code show?
    let friends = ["Meera", "Arjun"];
    friends.push("Kabir");
    friends.push("Aman");
    show(friends.length);
11. 11.True or false: photos on two devices fits saving in the cloud. (a) False (b) True
12. 12.Which of these fits saving in the cloud? (a) the sound on/off setting (b) a draft you are typing (c) notes to read offline (d) chat messages to friends
13. 13.💾 What number does this code show?
    let notes = ["Hindi", "Sports"];
    notes.push("Music");
    show(notes.length);
14. 14.💾 What number does this code show?
    let lives = 6;
    lives = lives - 1;
    lives = lives + 2;
    show(lives);
15. 15.💾 Which works with no internet at all? (a) a cloud backup (b) a cloud leaderboard (c) data saved on the phone (d) a shared chat
16. 16.💾 pop() takes off the last item. What does this code show?
    let friends = ["Zoya", "Arjun", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Kabir (c) Arjun
17. 17.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Arjun", "Zoya"];
    show(friends[1]); (a) Arjun (b) Riya (c) Zoya
18. 18.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
19. 19.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Music", "Science", "Sports", "Maths"];
    show(notes[1]); (a) Art (b) Science (c) Sports (d) Music
20. 20.💾 What number does this code show?
    let friends = ["Riya", "Zoya", "Meera", "Aman"];
    friends.push("Kabir");
    friends.push("Arjun");
    show(friends.length);
21. 21.Which of these fits saving on the phone? (a) notes to read offline (b) a class leaderboard (c) chat messages to friends (d) a shared to-do list
22. 22.Which of these fits saving in the cloud? (a) a draft you are typing (b) the sound on/off setting (c) a shared to-do list (d) notes to read offline
23. 23.💾 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
24. 24.True or false: a class leaderboard fits saving on the phone. (a) False (b) True
25. 25.💾 What number does this code show?
    let score = 8;
    score = score - 5;
    score = score + 2;
    show(score);
26. 26.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 1 (d) 0
27. 27.💾 What number does this code show?
    let notes = ["Hindi", "Sports"];
    notes.push("Maths");
    notes.push("Art");
    show(notes.length);
28. 28.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Stars", "Rain"];
    show(songs[0]); (a) Ocean (b) Rain (c) Stars
29. 29.💾 What number does this code show?
    let songs = ["Kites", "Stars"];
    songs.push("Sunrise");
    show(songs.length);
30. 30.💾 What number does this code show?
    let lives = 7;
    lives = lives - 4;
    lives = lives + 3;
    show(lives);
31. 31.💾 pop() takes off the last item. What does this code show?
    let notes = ["Science", "Maths", "Sports", "Hindi", "Art"];
    notes.pop();
    show(notes[notes.length - 1]); (a) Science (b) Maths (c) Sports (d) Hindi
32. 32.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Zoya", "Meera"];
    friends.pop();
    show(friends[friends.length - 1]); (a) Zoya (b) Riya (c) Meera
33. 33.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Monsoon", "Sunrise"];
    show(songs[2]); (a) Ocean (b) Monsoon (c) Sunrise
34. 34.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Maths", "Sports", "Science", "Music"];
    show(notes[0]); (a) Sports (b) Science (c) Art (d) Maths
35. 35.💾 What number does this code show?
    let lives = 3;
    lives = lives - 1;
    lives = lives + 2;
    show(lives);
36. 36.💾 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
37. 37.💾 Which can hold many values in order? (a) a button (b) a switch (c) a list (d) a single number
38. 38.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
39. 39.Which of these fits saving on the phone? (a) chat messages to friends (b) a class leaderboard (c) a shared to-do list (d) your last game level
40. 40.💾 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

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